Lightweight component of hybrid

ABSTRACT

The present invention relates to lightweight components of hybrid design, also termed hybrid component or hollow-chamber lightweight component, composed of a parent body which is composed of galvanized iron and which is reinforced by means of thermoplastics and is suitable for the transmission of high mechanical loads.

The present invention relates to lightweight components of hybriddesign, also termed hybrid component or hollow-chamber lightweightcomponent, composed of a parent body which is composed of galvanizediron and which is reinforced by means of thermoplastics and is suitablefor the transmission of high mechanical loads, where particular flowaids are added to the thermoplastic in order to improve its physicalproperties.

These lightweight components of appropriate design are used for vehicleparts, or in load-bearing elements of office machinery, or householdmachinery or other machinery, or in design elements for decorativepurposes or the like.

BACKGROUND OF THE INVENTION

A feature of lightweight components of hybrid design, hereinafter alsotermed hybrid components, is interlock connectioning of a parent bodymostly composed of metal, or of a hollow body which is, if appropriate,of shell type, to a plastics part joined onto or introduced into thesame. For the purposes of the present invention, they are also termedlightweight components, and in the case of shell-type components arealso termed hollow-chamber lightweight components.

German Offenlegungsschrift 27 50 982 discloses a non-releasableconnection involving two or more parts, preferably composed of metal,where the connection is composed of plastic and is produced in a mouldwhich receives the parts to be connected, for example by theinjection-moulding process. EP-A 0 370 342 discloses a lightweightcomponent of hybrid design composed of a shell-type parent body, theinterior of which has reinforcing ribs securely connected to the parentbody, in that the reinforcing ribs are composed of moulded-on plasticand their connection to the parent body is achieved at discreteconnection sites by way of perforations in the parent body, where theplastic extends through these and across the area of the perforations,achieving a secure interlock connection.

WO 2002/068257 A1 discloses “integrated structures” composed of metaland plastic, describing a large number of means for connecting the twocomponents securely to one another. WO 2004/071741 A1 discloses thealternative procedure, namely using two operations first to mould theplastic onto the shell-type metal part in such a way that the plasticpasses through openings in the metal part and leaves flash material onthe other side, with an additional conversion operation then requiredbefore this material leads to a secure interlock connection. EP 1 294552 B1 discloses that, for the production of a hybrid component, it ispossible that the metal core has been not completely, but onlysectionally, overmoulded by the plastic, to give a secure interlockconnection. WO 2004/011315 A1 describes a further variant, in which themetal part provides, both above and below, openings for the secureinterlock connection with the overmoulded plastic. WO 2001/38063 A1describes a composite plastics part composed of at least two sheet-likeworkpieces of different material, for example plastic and metal, or ofdifferent metals or plastics, where the workpieces have been connectedto one another in their peripheral region, and the connection iscomposed of moulded-on thermoplastic. EP 1 223 032 A2 discloses asheet-type lightweight component of hybrid design. U.S. Pat. No.6,761,187 B1 discloses a hybrid component in the form of a channel or ofa tube with integrated closure composed of a thermoplastic.

It was quickly recognized that lightweight components of hybrid designhave excellent suitability wherever high stability, high energyabsorption in the event of a crash, and weight saving are important,i.e. in the construction of motor vehicles, for example. EP 0 679 565 B1discloses the front end of a motor vehicle with at least one rigidtransverse bar which extends over most of the length of the front end,with at least one support part which is composed of plastic and which iscast onto the end region of the rigid transverse bar. EP 1 032 526 B1discloses a load-bearing structure for the front module of a motorvehicle composed of a steel sheet parent body, of an unreinforcedamorphous thermoplastic material, of a glass-fibre-reinforcedthermoplastic, and also of a rib structure composed of, for example,polyamide. DE 100 53 840 A1 discloses a bumper system or energy-absorberelement composed of oppositely arranged metal sheets and connection ribscomposed of thermoplastic or thermoset. WO 2001/40009 A1 discloses theuse of hybrid technology in brake pedals, clutch pedals or acceleratorpedals of motor vehicles. EP 1 211 164 B1 in turn describes the supportstructure for a motor vehicle radiator arrangement, using a hybridstructure. DE 101 50 061 A1 discloses the upper transverse member in thevehicle front module of hybrid design. U.S. Pat. No. 6,688,680 B1describes a transverse member of hybrid design in a motor vehicle. EP 1380 493 A2 gives another example of a front end panel of a motorvehicle, but here the material is not injected around all of the metalpart but takes the form of webs bracketing the same. Lightweightcomponents of hybrid design can be used not only for front ends orpedals but also anywhere in the bodywork of a vehicle. Examples of thisare provided by DE 100 18 186 B4 for a vehicle door with door casing, EP1 232 935 A1 for the actual bodywork of a vehicle, and DE 102 21 709 A1for the load-bearing elements of motor vehicles.

High-flowability thermoplastic compositions are of interest for a widevariety of shaping processes, such as injection-moulding applications.By way of example, thin-walled components in the electrical andelectronics industries and in the motor vehicle industry demand lowviscosities of the thermoplastic composition, to permit filling of themould while using minimum filling pressures or clamping forces for thecorresponding injection-moulding machinery. This is also relevant to thesimultaneous charging of a plurality of injection-moulded components byway of a shared gating system in what are known as multi-cavity moulds.Furthermore, low-viscosity thermoplastic compositions can also oftenachieve shorter cycle times. Good flowabilities are also specificallyvery important in the case of highly filled thermoplastic compositions,for example those with glass-fibre content and/or mineral content above40% by weight.

However, it has now become apparent that the secure metal-plasticcomposite in the abovementioned applications is primarily achieved viathe perforations in the metal and the thermoplastic flowing through theperforations. Disadvantages of this are firstly that additional amountsof thermoplastic are required, thus increasing weight, and that thesecure interlock connection is present primarily at the perforationsunless additional webs according to EP-A 13 80 493 are provided. Aconsiderable portion of the metal surface is therefore not available atall for secure interlock connection of metal to plastic.

SUMMARY OF THE INVENTION

The object of the present invention therefore consisted in producinghollow-chamber lightweight components of hybrid design which firstlyhave the advantages known from the prior art, e.g. high bucklingresistance, high torsional stability, relatively high strength,relatively low weight, and relatively low mould temperatures duringproduction, but where the metal-plastic composite is not achieved by wayof individual perforations of, or webs around, the metal, but insteadinvolves the entire contact surface of the geometry of the plastic onthe metal surface.

The object is achieved, and the present invention therefore provides,lightweight components composed of a parent body composed of galvanizediron and having reinforcing structures, where the reinforcing structureshave been securely connected to the parent body and are composed ofmoulded-on thermoplastic, characterized in that the thermoplasticpolymer moulding compositions used comprise polyamide mouldingcompositions which comprise from 99.99 to 10 parts by weight, preferablyfrom 99.5 to 40 parts by weight, particularly preferably from 99.0 to 55parts by weight, of at least one aliphatic, semicrystalline,thermoplastic polyamide, and in that the galvanized iron has beenpretreated by a process from the group of acid treatment, sodatreatment, amine treatment, anodic treatment, base treatment or lasertreatment.

DETAILED DESCRIPTION OF THE INVENTION

For clarification, it should be noted that the scope of the inventionencompasses any desired combination of all of the definitions andparameters listed above in general terms or in preferred ranges.

Polyamides to be used with preference are nylon-6 (PA 6) and nylon-6,6(PA 66) with relative solution viscosities of from 2.0 to 4.0 (measuredin m-cresol at 25° C.), and particularly preferably nylon-6 withrelative solution viscosity of from 2.3 to 2.6 (measured in m-cresol at25° C.), or a mixture composed of

-   A) from 99.99 to 10 parts by weight, preferably from 99.5 to 40    parts by weight, particularly preferably from 99.0 to 55 parts by    weight, of polyamide and with at least one component B) from 0.01 to    50 parts by weight, preferably from 0.25 to 20 parts by weight,    particularly preferably from 1.0 to 15 parts by weight, of an    additional flow improver from the group of-   B1) a copolymer composed of at least one olefin, preferably an    α-olefin, with at least one methacrylate or acrylate of an aliphatic    alcohol, preferably of an aliphatic alcohol having from 1 to 30    carbon atoms, with MFI of not less than 100 g/10 min, the MFI (melt    flow index) being measured or determined at 190° C. using a test    weight of 2.16 kg, or-   B2) a highly branched or hyperbranched polycarbonate with an OH    number of from 1 to 600 mg KOH/g of polycarbonate (to DIN 53240,    Part 2), or-   B3) a highly branched or hyperbranched polyester of A_(x)B_(y) type,    where x is at least 1.1 and y is at least 2.1, or-   B4) a polyalkylene glycol ester (PAGE) with low molecular weight of    the general formula (I)    R—COO—(Z—O)_(n)OC—R  (I)    -   in which    -   R is a branched or straight-chain alkyl group having from 1 to        20 carbon atoms,    -   Z is a branched or straight-chain C₂ to C₁₅ alkylene group, and    -   n is a whole number from 2 to 20, or        a mixture of B1) with B2) or of B2) with B3) or of B1) with B3)        or of B1) with B2) and with B3) or of B1) with B4) or of B2)        with B4) or of B3) with B4) or a ternary mixture of components        B1) to B4), in each case with A), where the secure interlock        connection between parent body and thermoplastic is achieved by        way of the galvanized iron surface of the parent body.

However, according to the invention, the term polyamide also encompassespolyamides which contain macromolecular chains having a star-shapedstructure and which contain linear macromolecular chains. Thesepolyamides, the structure of which provides improved flow, are obtainedaccording to DE 699 09 629 T2 by polymerising a mixture of monomers,where the mixture encompasses at least

-   a) monomers of the general formula (II) R₁-(-A-Z)_(m),-   b) monomers of the formula (IIIa) X—R₂—Y and (IIIb) R₂—NH—C═O,-   c) monomers of the general formula (IV) Z—R₃—Z, in which

R₁ is a linear or cyclic, aromatic or aliphatic hydrocarbon radicalwhich contains at least two carbon atoms and which can containheteroatoms,

A is a covalent bond or an aliphatic hydrocarbon radical having from 1to 6 carbon atoms,

Z is a primary amine radical or a carboxy group,

R₂ and R₃ are identical or different, being aliphatic, cycloaliphatic oraromatic, substituted or unsubstituted hydrocarbon radicals whichcontain from 2 to 20 carbon atoms and which can contain heteroatoms, and

Y is a primary amine radical, if X is a carbonyl radical, or Y is acarbonyl radical, if X is a primary amine radical, where m is a wholenumber from 3 to 8.

The molar concentration of the monomers of the formula (II) in themonomer mixture is from 0.1% to 2%, that of the monomers of the formula(IV) is from 0.1% to 2%, and the balance here making up 100% correspondsto the monomers of the general formulae (IIIa) and (IIIb). Thesepolyamides may be used independent from using component B) as thesepolyamides show already enhanced fluidity because of their star-shapedstructure.

Galvanized iron is produced by using zinc to coat iron structures oriron sheets, in order to protect them from rust. The iron articles orsteel articles here are pickled using dilute sulphuric acid comprisingsome tar or tin salt and copper sulphate, and are sand-blasted andimmersed in ammonium chloride solution, dried in a heated chamber andare then, while still hot, immersed in zinc which has been heated towell above its melting point, and which has a covering of ammoniumchloride to prevent oxidation.

The galvanized articles are placed in water, abraided with a brush, anddried in sawdust. Relatively small articles are immersed in largenumbers in the molten zinc and removed after one minute using aperforated ladle, and heated to red heat under wood-charcoal powder in areverberatory furnace, until excess zinc has been removed by melting.

In galvanized iron, the zinc is positive and is the only materialoxidized, while even the exposed iron remains uncorroded. The protectiveeffect of the zinc extends to distances of from 4 to 6 mm in air, andmuch further under water. The galvanizing process is very widely usedbecause of the said advantages, and particular apparatuses are used topermit convenient handling of the metal sheet and wire. The zinc ismelted in iron troughs which have an internal lining of clay, or inmasonry basins, and the component to be galvanized is placed in themolten metal or is passed through the bath at an appropriate speed.

Sheet-metal parts preferred according to the invention comprise from 45to 300 g of zinc for each square meter of area, and the strength of thezinc layer can therefore be assumed to be from 0.006 to 0.043 mm.

Iron is sometimes first electrogalvanized, to provide more secureadhesion of the molten zinc. Another method adequate for this purposeplaces the pickled and sand-blasted articles in a zinc chloride solutioncomprising ammonium chloride in a zinc box, and removes them after twominutes, dries them on a metal sheet heated from below, and immediatelyimmerses them in the molten zinc.

According to the invention, the galvanized parent bodies to be usedaccording to the invention, composed of steel or of iron, are subjectedto a further surface treatment, in order to achieve a secure interlockconnection between parent body and thermoplastic. For the purposes ofthe present invention, it has specifically been found that a secureinterlock connection is not achieved simply by galvanizing the ironparent body or steel parent body. Pretreatment of the galvanizediron/steel parent body is required according to the invention and can inprinciple be achieved by various processes. Pretreatment processesaccording to the invention from the group of acid treatment, sodatreatment, amine treatment, anodic treatment, base treatment or lasertreatment are used here. In one preferred embodiment of the presentinvention, other surface modifications can additionally be used toincrease the zinc surface area prepared by the types of treatmentmentioned. One preferred embodiment here uses graduatedadhesion-promoter layers (plastic-metal) which are applied by thermalspraying, and which provide a different method of increasing adhesion.

EP 1 958 763 A1 or EP 1 559 541 A1, the entire content of which isincorporated by way of reference into the present invention, giveexamples of the abovementioned pretreatment methods that are preferredaccording to the invention. Accordingly, for the acid treatment it ispreferable to use inorganic acids, and particularly preferably aqueoussolutions of the said inorganic acids, in particular hydrochloric acid,sulphuric acid, nitric acid, or an aqueous solution of ammonium hydrogenfluoride.

For the soda treatment it is preferable to use caustic soda (NaOH).

For the amine treatment, it is preferable to use ammonia, hydrazine orthe aqueous solution of an organic amine. For the purposes of thepresent invention, preferred organic amines are amines from the group ofmethylamine, dimethylamine, trimethylamine, ethylamine, diethylamine,triethylamine, ethylenediamine, ethanolamine, allylamine, ethanolamine,diethanolamine, triethanolamine, aniline and the like.

For the anodic treatment, the galvanized iron/steel part or thegalvanized iron parent body is first prepared so as to remove oils orfats, and then is subjected to alkali treatment, and finally iselectrolytically coated by an oxide layer in an anodic process, in anacidic aqueous solution. It is preferable that the alkali treatment usesan aqueous solution of caustic soda, at a concentration of from 10 to20%, at from 50 to 90 degrees Celsius, followed by chemical polishing.In this process, the galvanized component is immersed for a few secondsin a highly concentrated aqueous solution of an inorganic acid,preferably nitric acid, phosphoric acid, or sulphuric acid, or the like,at from 80 to 100 degrees Celsius.

For the alkali treatment process, it is preferable to use aqueoussolutions of alkali metal hydroxides or of alkaline earth metalhydroxides or sodium carbonate or potassium carbonate. Particularlypreferred hydroxides are hydroxides from the group of sodium hydroxide,potassium hydroxide, calcium hydroxide, strontium hydroxide, bariumhydroxide, or radium hydroxide.

For the laser treatment, pulsed Nd:YAG laser radiation is used ifappropriate in combination with a galvanometric scan system. This methodcan apply various structures to the zinc surface of the iron parentbody. Preferred structures are a point structure with a structuraldensity of 0.15, a linear structure with a structural density of 0.31,or a cross structure with a structural density of 0.53. The width of thestructures is preferably 20 micrometers. The depth of the structures ispreferably 30 micrometers. The separation is preferably 100 micrometers.(Joining Plastics, 3/08 pages 210-217).

For the purposes of the present invention, galvanized iron thereforealways means galvanized parent bodies composed of iron or steel whichhave additionally been subjected to a surface treatment, where apretreatment from the group of acid treatment, soda treatment, aminetreatment, anodic treatment, base treatment, or laser treatment has beencarried out.

In one preferred embodiment, the secure interlock connection betweenmoulded-on thermoplastic and the parent body composed of galvanized ironcan also be achieved by way of discrete connection sites, specificallyby way of perforations in the parent body, where the thermoplasticpasses through these perforations and extends over the area of theperforations, thus additionally reinforcing the secure interlockconnection which is in any case already being achieved by way of thegalvanized surface of the iron parent body.

The moulding-on of the thermoplastic is then preferably achieved in oneoperation. In the event that the parent body additionally still hasperforations that require overmoulding, the procedure for themoulding-on and overmoulding of the thermoplastic can be carried out inone, two, or three or more steps, as also can the forming processcarried out on the flash material on the opposite side, to give a plug.

The parent body composed of galvanized iron preferably has a shell-typeshape, particularly preferably a U shape, in order to accept reinforcingstructures, such as reinforcing ribs composed of thermoplastic. Theparent body composed of galvanized iron can also have a different shape,in the case of vehicle doors or of the alternative components listed ata later stage below for a motor vehicle. The three-dimensional shape ofthe parent body composed of galvanized iron is in essence determined viathe shape of the moulding to be produced.

The method of processing of the thermoplastic when it is used in theproduction of lightweight components of hybrid design according to theinvention involves known shaping processes, preferably injectionmoulding, melt extrusion, compression moulding, stamping or blowmoulding.

According to the invention, polyamide is used as thermoplastic orcomponent A) in the moulding compositions to be processed. Polyamidespreferred according to the invention are described by way of example inKunststoff-Taschenbuch [Plastics Handbook] (Ed. Saechtling), 1989edition, which also mentions sources. The person skilled in the art isaware of processes for the production of these polyamides. The effectsto be achieved are apparent with all of the variations known in theprior art cited above for the use of hybrid technology, irrespective ofwhether the thermoplastic is securely connected only in part or acrossits entire surface to the galvanized iron parent body, or, as in thecase of EP 1 380 493 A2, merely forms a web surrounding the same, andirrespective of whether the thermoplastic is additionally held in placeby adhesive bonding or is connected to the galvanized iron parent bodyby, for example, a laser, or, as in WO 2004/071741, an additionaloperation is used to obtain secure interlock connection of plastics partand metal part.

Preferred polyamides to be used as component A) are nylon-6 (PA 6) ornylon-6,6 (PA 66), or blends comprising primarily polyamide.

Polyamides to be used with particular preference according to theinvention as component A) are semicrystalline polyamides which can beproduced starting from diamines and dicarboxylic acids and/or fromlactams having at least 5 ring members or from corresponding aminoacids. Starting materials that can be used for this purpose arealiphatic and/or aromatic dicarboxylic acids, e.g. adipic acid, 2,2,4-and 2,4,4-trimethyladipic acid, azelaic acid, sebacic acid, isophthalicacid, terephthalic acid, aliphatic and/or aromatic diamines, e.g.tetramethylenediamine, hexamethylenediamine, 1,9-nonanediamine, 2,2,4-and 2,4,4-trimethylhexamethylenediamine, the isomericdiaminodicyclohexylmethanes, diaminodicyclohexylpropanes,bisaminomethylcyclo-hexane, phenylenediamines, xylylenediamines,aminocarboxylic acids, e.g. aminocaproic acid, or the correspondinglactams. Copolyamides composed of a plurality of the monomers mentionedare included.

Polyamides preferred according to the invention are those produced fromcaprolactams, very particularly preferably from ε-caprolactam, and mostof the compounded materials based on PA 6, on PA 66, and on otheraliphatic and/or aromatic polyamides or the corresponding copolyamides,where these have from 3 to 11 methylene groups for each polyamide groupin the polymer chain.

Semicrystalline polyamides to be used according to the invention ascomponent A) can also be used in a mixture with other polyamides and/orwith further polymers. It is also possible, therefore, to use polyamideswhich accord with DE 699 09 629 T2 in that the percentage by number ofmacromolecular chains of star type present is from 50% to 90%.

Conventional additives can be admixed in the melt of the polyamides, orapplied to the surface, examples being mould-release agents, stabilizersand/or flow aids.

In one alternative embodiment, however, it is also possible to userecycled PA materials, if appropriate in a mixture with polyalkyleneterephthalates, such as polybutylene terephtalates (PBT).

According to the invention, the term recyclates encompasses

-   1) “post-industrial recyclates”, which are production wastes arising    during the polycondensation reaction or sprues arising during    processing by injection moulding, start-up products from injection    moulding or extrusion, or edge cuts of extruded sheets or foils, and-   2) “post-consumer recyclates”, which are plastics items collected by    the final consumer after use, and treated.

Both types of recyclate can be used either in the form of regrind or inthe form of pellets. In the latter case, the crude recyclates are meltedin an extruder, after separation and purification, and pelletized. Thismostly facilitates handling and free flow, and metering for furthersteps of processing.

It is possible to use either pelletized recyclates or those in the formof regrind, but the maximum edge length here should be 10 mm, preferablybelow 8 mm.

If the intention is that flow improver is also to be added to thepolyamide, the moulding compositions to be used according to theinvention can comprise at least one component B), where the component B)used can comprise flow improvers from the group of B1) and/or B2) and/orB3) and/or B4).

According to the invention, B1) is copolymers, preferably randomcopolymers, composed of at least one olefin, preferably α-olefin, and ofat least one methacrylate or acrylate of an aliphatic alcohol. In onepreferred embodiment, these are random copolymers composed of at leastone olefin, preferably α-olefin, and of at least one methacrylate oracrylate with MFI of no less than 100 g/10 min, preferably no less than150 g/10 min, particularly preferably no less than 300 g/10 min, where,for the purposes of the present invention, the MFI (Melt Flow Index) wasmeasured or determined uniformly at 190° C. with a test weight of 2.16kg. The upper MFI limit is around 900 g/10 min.

In one particularly preferred embodiment, the copolymer B1) is composedof less than 4% by weight, particularly preferably less than 1.5% byweight and very particularly preferably 0% by weight, of monomer unitswhich contain further reactive functional groups selected from the groupconsisting of epoxides, oxetanes, anhydrides, imides, aziridines,furans, acids, amines and oxazolines.

Olefins, preferably α-olefins, suitable as constituent of the copolymersB1) preferably have from 2 to 10 carbon atoms and can be unsubstitutedor can have substitution by one or more aliphatic, cycloaliphatic oraromatic groups.

Preferred olefins are those selected from the group consisting ofethene, propene, 1-butene, 1-pentene, 1-hexene, 1-octene,3-methyl-1-pentene. Particularly preferred olefins are ethene andpropene, and ethene is particularly preferred.

Mixtures of the olefins described are also suitable.

In an embodiment to which further preference is given, the furtherreactive functional groups of the copolymer B1), selected from the groupconsisting of epoxides, oxetanes, anhydrides, imides, aziridines,furans, acids, amines, oxazolines, are introduced exclusively by way ofthe olefins into the copolymer B1).

The content of the olefin in the copolymer B1) is from 50 to 90% byweight, preferably from 55 to 75% by weight.

The copolymer B1) is further defined via the second constituentalongside the olefin. A suitable second constituent is alkyl esters orarylalkyl esters of acrylic acid or methacrylic acid whose alkyl orarylalkyl group is formed from 1 to 30 carbon atoms. The alkyl orarylalkyl group here can be linear or branched, and also can containcycloaliphatic or aromatic groups, and alongside this can also havesubstitution by one or more ether or thioether functions. Other suitablemethacrylates or acrylates in this connection are those synthesized froman alcohol component based on oligoethylene glycol or on oligopropyleneglycol having only one hydroxy group and at most 30 carbon atoms.

By way of example, the alkyl group or arylalkyl group of themethacrylate or acrylate can have been selected from the groupconsisting of methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl,tert-butyl, sec-butyl, 1-pentyl, 1-hexyl, 2-hexyl, 3-hexyl, 1-heptyl,3-heptyl, 1-octyl, 1-(2-ethyl)hexyl, 1-nonyl, 1-decyl, 1-dodecyl,1-lauryl or 1-octadecyl. Preference is given to alkyl groups orarylalkyl groups having from 6 to 20 carbon atoms. Preference isparticularly also given to branched alkyl groups which have the samenumber of carbon atoms as linear alkyl groups but give a lower glasstransition temperature T_(G).

According to the invention, an aryl group is a molecular moiety based onan aromatic skeleton, preferably being a phenyl radical.

Particular preference according to the invention is given to copolymersB1) in which the olefin is copolymerized with 2-ethylhexyl acrylate.Mixtures of the acrylates or methacylates described are also suitable.

It is preferable here to use more than 60% by weight, particularlypreferably more than 90% by weight and very particularly preferably 100%by weight, of 2-ethylhexyl acrylate, based on the total amount ofacrylate and methacrylate in copolymer B1).

In an embodiment to which further preference is given, the furtherreactive functional groups selected from the group consisting ofepoxides, oxetanes, anhydrides, imides, aziridines, furans, acids,amines, oxazolines in the copolymer B1) are introduced exclusively byway of the acrylate or methacrylate into the copolymer B1).

The content of the acrylate or methacrylate in the copolymer B1) is from10 to 50% by weight, preferably from 25 to 45% by weight.

A feature of suitable copolymers B1) is not only their constitution butalso their low molecular weight, their MFI value (Melt Flow Index)measured at 190° C. with a load of 2.16 kg being at least 100 g/10 min,preferably at least 150 g/10 min, particularly preferably at least 300g/10 min The upper MFI limit is around 900 g/10 min.

Copolymers particularly suitable as component B1) are those selectedfrom the group of the materials supplied by Atofina with trade markLotryl® EH, these usually being used as hot-melt adhesives.

The moulding compositions according to the invention can comprise, ascomponent B), as an alternative to B1) or in addition to B1), from 0.01to 50% by weight, preferably from 0.5 to 20% by weight and in particularfrom 0.7 to 10% by weight, of B2) at least one highly branched orhyperbranched polycarbonate with an OH number of from 1 to 600 mg KOH/gof polycarbonate, preferably from 10 to 550 mg KOH/g of polycarbonateand in particular from 50 to 550 mg KOH/g of polycarbonate (to DIN53240, Part 2) or of at least one hyperbranched polyester as componentB3) or a mixture of B1) with B2) or of B2) with B3) or of B1) with B3)or a mixture of B1) with B2) and with B3).

For the purposes of this invention, hyperbranched polycarbonates B2) arenon-crosslinked macromolecules having hydroxy groups and carbonategroups, these having both structural and molecular non-uniformity. Theirstructure may firstly be based on a central molecule in the same way asdendrimers, but with non-uniform chain length of the branches. Secondly,they may also have a linear structure with functional pendant groups, orelse they may combine the two extremes, having linear and branchedmolecular portions. See also P. J. Flory, J. Am. Chem. Soc. 1952, 74,2718, and H. Frey et al., Chem. Eur. J. 2000, 6, no. 14, 2499 for thedefinition of dendrimeric and hyperbranched polymers.

“Hyperbranched” in the context of the present invention means that thedegree of branching (DB), i.e. the average number of dendritic linkagesplus the average number of end groups per molecule, is from 10 to 99.9%,preferably from 20 to 99%, particularly preferably from 20 to 95%.

“Dendrimeric” in the context of the present invention means that thedegree of branching is from 99.9 to 100%. See H. Frey et al., ActaPolym. 1997, 48, 30 for the definition of “degree of branching”.

Component B2) preferably has a number-average molar mass M_(n) of from100 to 15 000 g/mol, preferably from 200 to 12 000 g/mol, and inparticular from 500 to 10 000 g/mol (GPC, PMMA standard).

The glass transition temperature Tg is in particular from −80 to +140°C., preferably from −60 to 120° C. (according to DSC, DIN 53765).

In particular, the viscosity (mPas) at 23° C. (to DIN 53019) is from 50to 200 000, in particular from 100 to 150 000, and very particularlypreferably from 200 to 100 000.

Component B2) is preferably obtainable via a process which comprises atleast the following steps:

-   a) reaction of at least one organic carbonate (CA) of the general    formula RO[(CO)]_(n)OR with at least one aliphatic,    aliphatic/aromatic or aromatic alcohol (AL) which has at least 3 OH    groups, with elimination of alcohols ROH to give one or more    condensates (K), where each R, independently of the others, is a    straight-chain or branched aliphatic, aromatic/aliphatic or aromatic    hydrocarbon radical having from 1 to 20 carbon atoms, and where the    radicals R may also have bonding to one another to form a ring, and    n is a whole number from 1 to 5, or-   ab) reaction of phosgene, diphosgene, or triphosgene with an alcohol    (AL) mentioned under a), with elimination of hydrogen chloride-   b) intermolecular reaction of the condensates (K) to give a highly    functional, highly branched, or highly functional, hyperbranched    polycarbonate, where the quantitative proportion of the OH groups to    the carbonates in the reaction mixture is selected in such a way    that the condensates (K) have an average of either one carbonate    group and more than one OH group or one OH group and more than one    carbonate group.

Phosgene, diphosgene, or triphosgene may be used as starting material,but preference is given to organic carbonates.

Each of the radicals R of the organic carbonates (CA) used as startingmaterial and having the general formula RO(CO)OR is, independently ofthe others, a straight-chain or branched aliphatic, aromatic/aliphaticor aromatic hydrocarbon radical having from 1 to 20 carbon atoms. Thetwo radicals R may also have bonding to one another to form a ring. Theradical is preferably an aliphatic hydrocarbon radical, and particularlypreferably a straight-chain or branched alkyl radical having from 1 to 5carbon atoms, or a substituted or unsubstituted phenyl radical.

In particular, use is made of simple carbonates of the formula RO(CO)OR;n is preferably from 1 to 3, in particular 1.

By way of example, dialkyl or diaryl carbonates may be prepared from thereaction of aliphatic, araliphatic, or aromatic alcohols, preferablymonoalcohols, with phosgene. They may also be prepared by way ofoxidative carbonylation of the alcohols or phenols by means of CO in thepresence of noble metals, oxygen, or NO_(x). In relation to preparationmethods for diaryl or dialkyl carbonates, see also “Ullmann'sEncyclopedia of Industrial Chemistry”, 6th edition, 2000 ElectronicRelease, Verlag Wiley-VCH.

Examples of suitable carbonates comprise aliphatic, aromatic/aliphaticor aromatic carbonates, such as ethylene carbonate, propylene 1,2- or1,3-carbonate, diphenyl carbonate, ditolyl carbonate, dixylyl carbonate,dinaphthyl carbonate, ethyl phenyl carbonate, dibenzyl carbonate,dimethyl carbonate, diethyl carbonate, dipropyl carbonate, dibutylcarbonate, diisobutyl carbonate, dipentyl carbonate, dihexyl carbonate,dicyclohexyl carbonate, diheptyl carbonate, dioctyl carbonate, didecylcarbonate, or didodecyl carbonate.

Examples of carbonates where n is greater than 1 comprise dialkyldicarbonates, such as di(tert-butyl) dicarbonate, or dialkyltricarbonates, such as di(tert-butyl) tricarbonate.

It is preferable to use aliphatic carbonates, in particular those inwhich the radicals comprise from 1 to 5 carbon atoms, e.g. dimethylcarbonate, diethyl carbonate, dipropyl carbonate, dibutyl carbonate, ordiisobutyl carbonate.

The organic carbonates are reacted with at least one aliphatic alcohol(AL) which has at least 3 OH groups, or with mixtures of two or moredifferent alcohols.

Examples of compounds having at least three OH groups comprise glycerol,trimethylolmethane, trimethylolethane, trimethylolpropane,1,2,4-butanetriol, tris(hydroxymethyl)amine, tris(hydroxyethyl)amine,tris(hydroxypropyl)amine, pentaerythritol, diglycerol, triglycerol,polyglycerols, bis(trimethylolpropane), tris(hydroxymethyl)isocyanurate, tris(hydroxyethyl) isocyanurate, phloroglucinol,trihydroxytoluene, trihydroxydimethylbenzene, phloroglucides,hexahydroxybenzene, 1,3,5-benzenetrimethanol,1,1,1-tris(4′-hydroxyphenyl)methane, 1,1,1-tris(4′-hydroxyphenyl)ethane,or sugars, e.g. glucose, trihydric or higher polyhydric polyetherolsbased on trihydric or higher polyhydric alcohols and ethylene oxide,propylene oxide, or butylene oxide, or polyesterols. Particularpreference is given here to glycerol, trimethylolethane,trimethylolpropane, 1,2,4-butanetriol, pentaerythritol, and also theirpolyetherols based on ethylene oxide or propylene oxide.

These polyhydric alcohols may also be used in a mixture with dihydricalcohols (AL′), with the proviso that the average OH functionality ofall of the alcohols used is greater than 2. Examples of suitablecompounds having two OH groups comprise ethylene glycol, diethyleneglycol, triethylene glycol, 1,2- and 1,3-propanediol, dipropyleneglycol, tripropylene glycol, neopentyl glycol, 1,2-, 1,3-, and1,4-butanediol, 1,2-, 1,3-, and 1,5-pentanediol, hexanediol,cyclopentanediol, cyclohexanediol, cyclohexanedimethanol,bis(4-hydroxycyclohexyl)methane, bis(4-hydroxycyclohexyl)ethane,2,2-bis(4-hydroxycyclohexyl)propane,1,1′-bis(4-hydroxyphenyl)-3,3,5-trimethylcyclohexane, resorcinol,hydroquinone, 4,4′-dihydroxyphenyl, bis(4-bis(hydroxy-phenyl) sulphide,bis(4-hydroxyphenyl) sulphone, bis(hydroxymethyl)benzene,bis-(hydroxymethyl)toluene, bis(p-hydroxyphenyl)methane,bis(p-hydroxyphenyl)ethane, 2,2-bis(hydroxyphenyl)propane,1,1-bis(p-hydroxyphenyl)cyclohexane, dihydroxybenzophenone, dihydricpolyether polyols based on ethylene oxide, propylene oxide, butyleneoxide, or mixtures of these, polytetrahydrofuran, polycaprolactone, orpolyesterols based on diols and dicarboxylic acids.

The diols serve for fine adjustment of the properties of thepolycarbonate. If use is made of dihydric alcohols, the ratio ofdihydric alcohols (AL′), to the at least trihydric alcohols (AL) is setby the person skilled in the art and depends on the desired propertiesof the polycarbonate. The amount of the alcohol(s) (AL′) is generallyfrom 0 to 39.9 mol %, based on the total amount of all of the alcohols(AL) and (AL′) taken together. The amount is preferably from 0 to 35 mol%, particularly preferably from 0 to 25 mol %, and very particularlypreferably from 0 to 10 mol %.

The reaction of phosgene, diphosgene, or triphosgene with the alcohol oralcohol mixture generally takes place with elimination of hydrogenchloride, and the reaction of the carbonates with the alcohol or alcoholmixture to give the highly functional highly branched polycarbonatetakes place with elimination of the monofunctional alcohol or phenolfrom the carbonate molecule.

The highly functional highly branched polycarbonates have termination byhydroxy groups and/or by carbonate groups after their preparation, i.e.with no further modification. They have good solubility in varioussolvents, e.g. in water, alcohols, such as methanol, ethanol, butanol,alcohol/water mixtures, acetone, 2-butanone, ethyl acetate, butylacetate, methoxypropyl acetate, methoxyethyl acetate, tetrahydrofuran,dimethylformamide, dimethylacetamide, N-methylpyrrolidone, ethylenecarbonate, or propylene carbonate.

For the purposes of this invention, a highly functional polycarbonate isa product which, besides the carbonate groups which form the polymerskeleton, further has at least three, preferably at least six, morepreferably at least ten, terminal or pendant functional groups. Thefunctional groups are carbonate groups and/or OH groups. There is inprinciple no upper restriction on the number of the terminal or pendantfunctional groups, but products having a very high number of functionalgroups can have undesired properties, such as high viscosity or poorsolubility. The highly functional polycarbonates of the presentinvention mostly have no more than 500 terminal or pendant functionalgroups, preferably no more than 100 terminal or pendant functionalgroups.

When preparing the highly functional polycarbonates B2), it is necessaryto adjust the ratio of the compounds comprising OH groups to phosgene orcarbonate in such a way that the simplest resultant condensate(hereinafter termed condensate (K)) comprises an average of either onecarbonate group or carbamoyl group and more than one OH group or one OHgroup and more than one carbonate group or carbamoyl group. The simpleststructure of the condensate (K) composed of a carbonate (A) and a di- orpolyalcohol (B) here results in the arrangement XYn or YnX, where X is acarbonate group, Y is a hydroxy group, and n is generally a number from1 to 6, preferably from 1 to 4, particularly preferably from 1 to 3. Thereactive group which is the single resultant group here is generallytermed “focal group” below.

By way of example, if during the preparation of the simplest condensate(K) from a carbonate and a dihydric alcohol the reaction ratio is 1:1,the average result is a molecule of XY type, illustrated by the generalformula (V).

During the preparation of the condensate (K) from a carbonate and atrihydric alcohol with a reaction ratio of 1:1, the average result is amolecule of XY₂ type, illustrated by the general formula (VI). Acarbonate group is focal group here.

During the preparation of the condensate (K) from a carbonate and atetrahydric alcohol, likewise with the reaction ratio 1:1, the averageresult is a molecule of XY₃ type, illustrated by the general formula(VII). A carbonate group is focal group here.

R in the formulae (V) to (VII) has the definition given above, and R¹ isan aliphatic or aromatic radical.

The condensate (K) may, by way of example, also be prepared from acarbonate and a trihydric alcohol, as illustrated by the general formula(VIII), the molar reaction ratio being 2:1. Here, the average result isa molecule of X₂Y type, an OH group being focal group here. In formula(VIII), R and R¹ are as defined in formulae (V) to (VII).

If difunctional compounds, e.g. a dicarbonate or a diol, are also addedto the components, this extends the chains, as illustrated by way ofexample in the general formula (IX). The average result is again amolecule of XY₂ type, a carbonate group being focal group.

In formula (IX), R² is an organic, preferably aliphatic radical, and Rand R¹ are as defined above.

It is also possible to use two or more condensates (K) for thesynthesis. Here, firstly two or more alcohols or two or more carbonatesmay be used. Furthermore, mixtures of various condensates of differentstructure can be obtained via the selection of the ratio of the alcoholsused and of the carbonates or the phosgenes. This may be illustratedtaking the example of the reaction of a carbonate with a trihydricalcohol. If the starting products are reacted in a ratio of 1:1, asshown in (VI), the result is an XY₂ molecule. If the starting productsare reacted in a ratio of 2:1, as shown in (VIII), the result is an X₂Ymolecule. If the ratio is from 1:1 to 2:1, the result is a mixture ofXY₂ and X₂Y molecules.

According to the invention, the simple condensates (K) described by wayof example in the formulae (V) to (IX) preferentially reactintermolecularly to form highly functional polycondensates, hereinaftertermed polycondensates (P). The reaction to give the condensate (K) andto give the polycondensate (P) usually takes place at a temperature offrom 0 to 250° C., preferably from 60 to 160° C., in bulk or insolution.

Use may generally be made here of any of the solvents which are inertwith respect to the respective starting materials. Preference is givento use of organic solvents, e.g. decane, dodecane, benzene, toluene,chlorobenzene, xylene, dimethylformamide, dimethylacetamide, or solventnaphtha.

In one embodiment, the condensation reaction is carried out in bulk. Toaccelerate the reaction, the phenol or the monohydric alcohol ROHliberated during the reaction can be removed by distillation from thereaction equilibrium if appropriate at reduced pressure.

If removal by distillation is intended, it is generally advisable to usethose carbonates which liberate alcohols ROH with a boiling point below140° C. during the reaction.

Catalysts or catalyst mixtures may also be added to accelerate thereaction. Suitable catalysts are compounds which catalyze esterificationor transesterification reactions, e.g. alkali metal hydroxides, alkalimetal carbonates, alkali metal hydrogencarbonates, preferably of sodium,of potassium, or of cesium, tertiary amines, guanidines, ammoniumcompounds, phosphonium compounds, organoaluminium, organotin,organozinc, organotitanium, organozirconium, or organobismuth compounds,or else what are known as double metal cyanide (DMC) catalysts, e.g. asdescribed in DE-A 10138216 or DE-A 10147712.

It is preferable to use potassium hydroxide, potassium carbonate,potassium hydrogencarbonate, diazabicyclooctane (DABCO),diazabicyclononene (DBN), diazabicycloundecene (DBU), imidazoles, suchas imidazole, 1-methylimidazole, or 1,2-dimethylimidazole, titaniumtetrabutoxide, titanium tetraisopropoxide, dibutyltin oxide, dibutyltindilaurate, stannous dioctoate, zirconium acetylacetonate, or mixturesthereof.

The amount of catalyst generally added is from 50 to 10 000 ppm byweight, preferably from 100 to 5000 ppm by weight, based on the amountof the alcohol mixture or alcohol used.

It is also possible to control the intermolecular polycondensationreaction via addition of the suitable catalyst or else via selection ofa suitable temperature. The average molecular weight of the polymer (P)may moreover be adjusted by way of the composition of the startingcomponents and by way of the residence time.

The condensates (K) and the polycondensates (P) prepared at an elevatedtemperature are usually stable at room temperature for a relatively longperiod.

The nature of the condensates (K) permits polycondensates (P) withdifferent structures to result from the condensation reaction, thesehaving branching but no crosslinking. Furthermore, in the ideal case,the polycondensates (P) have either one carbonate group as focal groupand more than two OH groups or else one OH group as focal group and morethan two carbonate groups. The number of the reactive groups here is theresult of the nature of the condensates (K) used and the degree ofpolycondensation.

By way of example, a condensate (K) according to the general formula(II) can react via triple intermolecular condensation to give twodifferent polycondensates (P), represented in the general formulae (X)and (XI).

In formula (X) and (XI), R and R¹ are as defined above.

There are various ways of terminating the intermolecularpolycondensation reaction. By way of example, the temperature may belowered to a range where the reaction stops and the product (K) or thepolycondensate (P) is storage-stable.

It is also possible to deactivate the catalyst, for example in the caseof basic catalysts via addition of Lewis acids or proton acids.

In another embodiment, as soon as the intermolecular reaction of thecondensate (K) has produced a polycondensate (P) with the desired degreeof polycondensation, a product having groups reactive toward the focalgroup of (P) may be added to the product (P) to terminate the reaction.In the case of a carbonate group as focal group, by way of example, amono-, di-, or polyamine may therefore be added. In the case of ahydroxy group as focal group, by way of example, a mono-, di-, orpolyisocyanate, or a compound comprising epoxy groups, or an acidderivative which reacts with OH groups, can be added to the product (P).

The highly functional polycarbonates are mostly prepared in a pressurerange from 0.1 mbar to 20 bar, preferably at from 1 mbar to 5 bar, inreactors or reactor cascades which are operated batchwise,semicontinuously, or continuously.

The inventive products can be further processed without furtherpurification after their preparation by virtue of the abovementionedadjustment of the reaction conditions and, if appropriate, by virtue ofthe selection of the suitable solvent.

In another preferred embodiment, the product is stripped, i.e. freedfrom low-molecular-weight, volatile compounds. For this, once thedesired degree of conversion has been reached the catalyst mayoptionally be deactivated and the low-molecular-weight volatileconstituents, e.g. monoalcohols, phenols, carbonates, hydrogen chloride,or volatile oligomeric or cyclic compounds, can be removed bydistillation, if appropriate with introduction of a gas, preferablynitrogen, carbon dioxide, or air, if appropriate at reduced pressure.

In another preferred embodiment, the polycarbonates may comprise otherfunctional groups besides the functional groups present at this stage byvirtue of the reaction. The functionalization may take place during theprocess to increase molecular weight, or else subsequently, i.e. aftercompletion of the actual polycondensation.

If, prior to or during the process to increase molecular weight,components are added which have other functional groups or functionalelements besides hydroxy or carbonate groups, the result is apolycarbonate polymer with randomly distributed functionalities otherthan the carbonate groups or hydroxy groups.

Effects of this type can, by way of example, be achieved via addition,during the polycondensation, of compounds which bear other functionalgroups or functional elements, such as mercapto groups, primary,secondary or tertiary amino groups, ether groups, derivatives ofcarboxylic acids, derivatives of sulphonic acids, derivatives ofphosphonic acids, silane groups, siloxane groups, aryl radicals, orlong-chain alkyl radicals, besides hydroxy groups, carbonate groups orcarbamoyl groups. Examples of compounds which may be used formodification by means of carbamate groups are ethanolamine,propanolamine, isopropanolamine, 2-(butylamino)ethanol,2-(cyclohexylamino)ethanol, 2-amino-1-butanol, 2-(2′-aminoethoxy)ethanolor higher alkoxylation products of ammonia, 4-hydroxypiperidine,1-hydroxyethylpiperazine, diethanolamine, dipropanolamine,diisopropanolamine, tris(hydroxymethyl)aminomethane,tris(hydroxy-ethyl)aminomethane, ethylenediamine, propylenediamine,hexamethylenediamine or isophoronediamine.

An example of a compound which can be used for modification withmercapto groups is mercaptoethanol. By way of example, tertiary aminogroups can be produced via incorporation of N-methyldiethanolamine,N-methyldipropanolamine or N,N-dimethylethanolamine. By way of example,ether groups may be generated via co-condensation of dihydric or higherpolyhydric polyetherols. Long-chain alkyl radicals can be introduced viareaction with long-chain alkanediols, and reaction with alkyl or aryldiisocyanates generates polycarbonates having alkyl, aryl, and urethanegroups, or urea groups.

Ester groups can be produced via addition of dicarboxylic acids,tricarboxylic acids, or, for example, dimethyl terephthalate, ortricarboxylic esters.

Subsequent functionalization can be achieved by using an additional stepof the process to react the resultant highly functional, highlybranched, or highly functional hyperbranched polycarbonate with asuitable functionalizing reagent which can react with the OH and/orcarbonate groups or carbamoyl groups of the polycarbonate.

By way of example, highly functional highly branched, or highlyfunctional hyperbranched polycarbonates comprising hydroxy groups can bemodified via addition of molecules comprising acid groups or isocyanategroups. By way of example, polycarbonates comprising acid groups can beobtained via reaction with compounds comprising anhydride groups.

Highly functional polycarbonates comprising hydroxy groups may moreoveralso be converted into highly functional polycarbonate polyether polyolsvia reaction with alkylene oxides, e.g. ethylene oxide, propylene oxide,or butylene oxide.

The improved-flow moulding compositions to be used for the production ofthe inventive hybrid-based lightweight components can comprise, ascomponent B3), at least one hyperbranched polyester of A_(x)B_(y) type,where

-   x is at least 1.1, preferably at least 1.3, in particular at least 2    and-   y is at least 2.1, preferably at least 2.5, in particular at least    3.

Use may also be made of mixtures as units A and/or B, of course.

An A_(x)B_(y)-type polyester is a condensate composed of an x-functionalmolecule A and a y-functional molecule B. By way of example, mention maybe made of a polyester composed of adipic acid as molecule A (x=2) andglycerol as molecule B (y=3).

For the purposes of this invention, hyperbranched polyesters B3) arenon-crosslinked macromolecules having hydroxy groups and carboxy groups,these having both structural and molecular non-uniformity. Theirstructure may firstly be based on a central molecule in the same way asdendrimers, but with non-uniform chain length of the branches. Secondly,they may also have a linear structure with functional pendant groups, orelse they may combine the two extremes, having linear and branchedmolecular portions. See also P. J. Flory, J. Am. Chem. Soc. 1952, 74,2718, and H. Frey et al., Chem. Eur. J. 2000, 6, no. 14, 2499 for thedefinition of dendrimeric and hyperbranched polymers.

“Hyperbranched” in the context of the present invention means that thedegree of branching (DB), i.e. the average number of dendritic linkagesplus the average number of end groups per molecule, is from 10 to 99.9%,preferably from 20 to 99%, particularly preferably from 20 to 95%.“Dendrimeric” in the context of the present invention means that thedegree of branching is from 99.9 to 100%. See H. Frey et al., ActaPolym. 1997, 48, 30 for the definition of “degree of branching”.

Component B3) preferably has a molecular weight of from 300 to 30 000g/mol, in particular from 400 to 25 000 g/mol, and very particularlyfrom 500 to 20 000 g/mol, determined by means of GPC, PMMA standard,dimethylacetamide eluent.

B3) preferably has an OH number of from 0 to 600 mg KOH/g of polyester,preferably from 1 to 500 mg KOH/g of polyester, in particular from 20 to500 mg KOH/g of polyester to DIN 53240, and preferably a COOH number offrom 0 to 600 mg KOH/g of polyester, preferably from 1 to 500 mg KOH/gof polyester, and in particular from 2 to 500 mg KOH/g of polyester.

The Tg (glass transition temperature) is preferably from −50° C. to 140°C., and in particular from −50 to 100° C. (by means of DSC, to DIN53765).

Preference is particularly given to those components B3) in which atleast one OH or COOH number is greater than 0, preferably greater than0.1, and in particular greater than 0.5.

The component B3) is obtainable via the processes described below, forexample by reacting

-   (m) one or more dicarboxylic acids or one or more derivatives of the    same with one or more at least trihydric alcohols    or-   (n) one or more tricarboxylic acids or higher polycarboxylic acids    or one or more derivatives of the same with one or more diols in the    presence of a solvent and optionally in the presence of an    inorganic, organometallic, or low-molecular-weight organic catalyst,    or of an enzyme. The reaction in solvent is the preferred    preparation method.

Highly functional hyperbranched polyesters B3) have molecular andstructural non-uniformity. Their molecular non-uniformity distinguishesthem from dendrimers, and they can therefore be prepared at considerablylower cost.

Among the dicarboxylic acids which can be reacted according to variant(m) are, by way of example, oxalic acid, malonic acid, succinic acid,glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid,sebacic acid, undecane-α,ω-dicarboxylic acid, dodecane-α,ω-dicarboxylicacid, cis- and trans-cyclohexane-1,2-dicarboxylic acid, cis- andtrans-cyclohexane-1,3-dicarboxylic acid, cis- andtrans-cyclohexane-1,4-dicarboxylic acid, cis- andtrans-cyclopentane-1,2-dicarboxylic acid, and cis- andtrans-cyclopentane-1,3-dicarboxylic acid, and the abovementioneddicarboxylic acids may have substitution by one or more radicalsselected from C₁-C₁₀-alkyl groups, such as methyl, ethyl, n-propyl,isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl,isopentyl, sec-pentyl, neopentyl, 1,2-dimethylpropyl, isoamyl, n-hexyl,isohexyl, sec-hexyl, n-heptyl, isoheptyl, n-octyl, 2-ethylhexyl,n-nonyl, and n-decyl, C₃-C₁₂-cycloalkyl groups, such as cyclopropyl,cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl,cyclononyl, cyclodecyl, cycloundecyl, and cyclododecyl; preference isgiven to cyclopentyl, cyclohexyl, and cycloheptyl; alkylene groups, suchas methylene or ethylidene, or C₆-C₁₄-aryl groups, such as phenyl,1-naphthyl, 2-naphthyl, 1-anthryl, 2-anthryl, 9-anthryl, 1-phenanthryl,2-phenanthryl, 3-phenanthryl, 4-phenanthryl, and 9-phenanthryl,preferably phenyl, 1-naphthyl, and 2-naphthyl, particularly preferablyphenyl.

Examples which may be mentioned as representatives of substituteddicarboxylic acids are: 2-methylmalonic acid, 2-ethylmalonic acid,2-phenylmalonic acid, 2-methylsuccinic acid, 2-ethylsuccinic acid,2-phenylsuccinic acid, itaconic acid, 3,3-dimethylglutaric acid.

Among the dicarboxylic acids which can be reacted according to variant(m) are also ethylenically unsaturated acids, such as maleic acid andfumaric acid, and aromatic dicarboxylic acids, such as phthalic acid,isophthalic acid or terephthalic acid.

It is also possible to use mixtures of two or more of the abovementionedrepresentative compounds.

The dicarboxylic acids may either be used as they stand or be used inthe form of derivatives.

Derivatives are preferably

-   -   the relevant anhydrides in monomeric or else polymeric form,    -   mono- or dialkyl esters, preferably mono- or dimethyl esters, or        the corresponding mono- or diethyl esters, or else the mono- and        dialkyl esters derived from higher alcohols, such as n-propanol,        isopropanol, n-butanol, isobutanol, tert-butanol, n-pentanol,        n-hexanol,    -   and also mono- and divinyl esters, and    -   mixed esters, preferably methyl ethyl esters.

However, it is also possible to use a mixture composed of a dicarboxylicacid and one or more of its derivatives. Equally, it is possible to usea mixture of two or more different derivatives of one or moredicarboxylic acids.

It is particularly preferable to use succinic acid, glutaric acid,adipic acid, phthalic acid, isophthalic acid, terephthalic acid, or themono- or dimethyl esters thereof. It is very particularly preferable touse adipic acid.

Examples of at least trihydric alcohols which may be reacted are:glycerol, butane-1,2,4-triol, n-pentane-1,2,5-triol,n-pentane-1,3,5-triol, n-hexane-1,2,6-triol, n-hexane-1,2,5-triol,n-hexane-1,3,6-triol, trimethylolbutane, trimethylolpropane orditrimethylolpropane, trimethylolethane, pentaerythritol ordipentaerythritol; sugar alcohols, such as mesoerythritol, threitol,sorbitol, mannitol, or mixtures of the above at least trihydricalcohols. It is preferable to use glycerol, trimethylolpropane,trimethylolethane, and pentaerythritol.

Examples of tricarboxylic acids or polycarboxylic acids which can bereacted according to variant (n) are benzene-1,2,4-tricarboxylic acid,benzene-1,3,5-tricarboxylic acid, benzene-1,2,4,5-tetracarboxylic acid,and mellitic acid.

Tricarboxylic acids or polycarboxylic acids may be used in the inventivereaction either as they stand or else in the form of derivatives.

Derivatives are preferably

-   -   the relevant anhydrides in monomeric or else polymeric form,    -   mono-, di-, or trialkyl esters, preferably mono-, di-, or        trimethyl esters, or the corresponding mono-, di-, or triethyl        esters, or else the mono-, di-, and triesters derived from        higher alcohols, such as n-propanol, isopropanol, n-butanol,        isobutanol, tert-butanol, n-pentanol, n-hexanol, or else mono-,        di-, or trivinyl esters    -   and mixed methyl ethyl esters.

It is also possible to use a mixture composed of a tri- orpolycarboxylic acid and one or more of its derivatives. It is likewisepossible to use a mixture of two or more different derivatives of one ormore tri- or polycarboxylic acids, in order to obtain component B3).

Examples of diols used for variant (n) are ethylene glycol,propane-1,2-diol, propane-1,3-diol, butane-1,2-diol, butane-1,3-diol,butane-1,4-diol, butane-2,3-diol, pentane-1,2-diol, pentane-1,3-diol,pentane-1,4-diol, pentane-1,5-diol, pentane-2,3-diol, pentane-2,4-diol,hexane-1,2-diol, hexane-1,3-diol, hexane-1,4-diol, hexane-1,5-diol,hexane-1,6-diol, hexane-2,5-diol, heptane-1,2-diol, 1,7-heptanediol,1,8-octanediol, 1,2-octanediol, 1,9-nonanediol, 1,10-decanediol,1,2-decanediol, 1,12-dodecanediol, 1,2-dodecanediol,1,5-hexadiene-3,4-diol, cyclopentanediols, cyclohexanediols, inositoland derivatives, (2)-methylpentane-2,4-diol,2,4-dimethylpentane-2,4-diol, 2-ethylhexane-1,3-diol,2,5-dimethylhexane-2,5-diol, 2,2,4-trimethylpentane-1,3-diol, pinacol,diethylene glycol, triethylene glycol, dipropylene glycol, tripropyleneglycol, polyethylene glycols HO(CH₂CH₂O)_(n)—H or polypropylene glycolsHO(CH[CH₃]CH₂O)_(n)—H or mixtures of two or more representativecompounds of the above compounds, where n is a whole number and n=4.One, or else both, hydroxy groups here in the abovementioned diols mayalso be replaced by SH groups. Preference is given to ethylene glycol,propane-1,2-diol, and diethylene glycol, triethylene glycol, dipropyleneglycol, and tripropylene glycol.

The molar ratio of the molecules A to molecules B in the A_(x)B_(y)polyester in the variants (m) and (n) is from 4:1 to 1:4, in particularfrom 2:1 to 1:2.

The at least trihydric alcohols reacted according to variant (m) mayhave hydroxy groups of which all have identical reactivity. Preferenceis also given here to at least trihydric alcohols whose OH groupsinitially have identical reactivity, but where reaction with at leastone acid group can induce a fall-off in reactivity of the remaining OHgroups as a result of steric or electronic effects. By way of example,this applies when trimethylolpropane or pentaerythritol is used.

However, the at least trihydric alcohols reacted according to variant(m) may also have hydroxy groups having at least two different chemicalreactivities.

The different reactivity of the functional groups here may derive eitherfrom chemical causes (e.g. primary/secondary/tertiary OH group) or fromsteric causes.

By way of example, the triol may comprise a triol which has primary andsecondary hydroxy groups, a preferred example being glycerol.

When the reaction is carried out according to variant (m), it ispreferable to operate in the absence of diols and of monohydricalcohols.

When the reaction is carried out according to variant (n), it ispreferable to operate in the absence of mono- or dicarboxylic acids.

The process is carried out in the presence of a solvent. By way ofexample, hydrocarbons are suitable, such as paraffins or aromatics.Particularly suitable paraffins are n-heptane and cyclohexane.Particularly suitable aromatics are toluene, ortho-xylene, meta-xylene,para-xylene, xylene in the form of an isomer mixture, ethylbenzene,chlorobenzene, and ortho- and meta-dichlorobenzene. Other solvents veryparticularly suitable in the absence of acidic catalysts are: ethers,such as dioxane or tetrahydrofuran, and ketones, such as methyl ethylketone and methyl isobutyl ketone.

The amount of solvent added is at least 0.1% by weight, based on theweight of the starting materials used and to be reacted, preferably atleast 1% by weight, and particularly preferably at least 10% by weight.It is also possible to use excesses of solvent, based on the weight ofstarting materials used and to be reacted, e.g. from 1.01 to 10 timesthe amount. Solvent amounts of more than 100 times the weight of thestarting materials used and to be reacted are not advantageous, becausethe reaction rate decreases markedly at markedly lower concentrations ofthe reactants, giving uneconomically long reaction times.

To carry out the process, operations may be carried out in the presenceof a dehydrating agent as additive, added at the start of the reaction.Suitable examples are molecular sieves, in particular 4 Å molecularsieve, MgSO₄, and Na₂SO₄. During the reaction it is also possible to addfurther dehydrating agent or to replace dehydrating agent by freshdehydrating agent. During the reaction it is also possible to remove thewater or alcohol formed by distillation and, for example, to use a watertrap.

The process may be carried out in the absence of acidic catalysts. It ispreferable to operate in the presence of an acidic inorganic,organometallic, or organic catalyst, or a mixture composed of two ormore acidic inorganic, organometallic, or organic catalysts.

Examples of acidic inorganic catalysts are sulphuric acid, phosphoricacid, phosphonic acid, hypophosphorous acid, aluminium sulphate hydrate,alum, acidic silica gel (pH=6, in particular =5), and acidic aluminiumoxide. Examples of other compounds which can be used as acidic inorganiccatalysts are aluminium compounds of the general formula Al(OR)₃ andtitanates of the general formula Ti(OR)₄, where each of the radicals Rmay be identical or different and is selected independently of theothers from C₁-C₁₀-alkyl radicals, such as methyl, ethyl, n-propyl,isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl,isopentyl, sec-pentyl, neopentyl, 1,2-dimethylpropyl, isoamyl, n-hexyl,isohexyl, sec-hexyl, n-heptyl, isoheptyl, n-octyl, 2-ethylhexyl,n-nonyl, and n-decyl, C₃-C₁₂-cycloalkyl radicals, such as cyclopropyl,cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl,cyclononyl, cyclodecyl, cycloundecyl, and cyclododecyl; preference isgiven to cyclopentyl, cyclohexyl, and cycloheptyl.

Each of the radicals R in Al(OR)₃ or Ti(OR)₄ is preferably identical andselected from isopropyl or 2-ethylhexyl.

Examples of preferred acidic organometallic catalysts are selected fromdialkyltin oxides R₂SnO, where R is defined as above. A particularlypreferred representative compound for acidic organometallic catalysts isdi-n-butyltin oxide, which is commercially available as “oxo-tin”, ordi-n-butyltin dilaurate.

Preferred acidic organic catalysts are acidic organic compounds having,by way of example, phosphate groups, sulphonic acid groups, sulphategroups, or phosphonic acid groups. Particular preference is given tosulphonic acids, such as para-toluenesulphonic acid. Acidic ionexchangers may also be used as acidic organic catalysts, e.g.polystyrene resins comprising sulphonic acid groups and crosslinked withabout 2 mol % of divinylbenzene.

It is also possible to use combinations of two or more of theabovementioned catalysts. It is also possible to use an immobilized formof those organic or organometallic, or else inorganic catalysts whichtake the form of discrete molecules.

If the intention is to use acidic inorganic, organometallic, or organiccatalysts, according to the invention the amount used is from 0.1 to 10%by weight, preferably from 0.2 to 2% by weight, of catalyst.

The preparation process for component B3) is carried out under an inertgas, for example under carbon dioxide, nitrogen or a noble gas, amongwhich particular mention may be made of argon. The inventive process iscarried out at temperatures of from 60 to 200° C. It is preferable tooperate at temperatures of from 130 to 180° C., in particular up to 150°C., or below that temperature. Maximum temperatures up to 145° C. areparticularly preferred, and temperatures up to 135° C. are veryparticularly preferred. The pressure conditions for the preparationprocess are not critical. It is possible to operate at markedly reducedpressure, e.g. at from 10 to 500 mbar. The process may also be carriedout at pressures above 500 mbar. The reaction at atmospheric pressure ispreferred for reasons of simplicity; however, conduct at slightlyincreased pressure is also possible, e.g. up to 1200 mbar. It is alsopossible to operate at markedly increased pressure, e.g. at pressures upto 10 bar. Reaction at atmospheric pressure is preferred. The reactiontime is usually from 10 minutes to 25 hours, preferably from 30 minutesto 10 hours, and particularly preferably from one to 8 hours.

Once the reaction has ended, the highly functional hyperbranchedpolyesters (B3) can easily be isolated, e.g. by removing the catalyst byfiltration and concentrating the mixture, the concentration process hereusually being carried out at reduced pressure. Other work-up methodswith good suitability are precipitation after addition of water,followed by washing and drying.

Component B3) can also be prepared in the presence of enzymes ordecomposition products of enzymes (according to DE-A 10 163 163). Forthe purposes of the present invention, the term acidic organic catalystsdoes not include the dicarboxylic acids reacted according to theinvention.

It is preferable to use lipases or esterases. Lipases and esterases withgood suitability are Candida cylindracea, Candida lipolytica, Candidarugosa, Candida antarctica, Candida utilis, Chromobacterium viscosum,Geotrichum viscosum, Geotrichum candidum, Mucor javanicus, Mucor mihei,pig pancreas, pseudomonas spp., pseudomonas fluorescens, Pseudomonascepacia, Rhizopus arrhizus, Rhizopus delemar, Rhizopus niveus, Rhizopusoryzae, Aspergillus niger, Penicillium roquefortii, Penicilliumcamembertii, or esterase from Bacillus spp. and Bacillusthermoglucosidasius. Candida antarctica lipase B is particularlypreferred. The enzymes listed are commercially available, for examplefrom Novozymes Biotech Inc., Denmark.

The enzyme is preferably used in immobilized form, for example on silicagel or Lewatit®. The processes for immobilizing enzymes are known, e.g.from Kurt Faber, “Biotransformations in Organic Chemistry”, 3rd edition1997, Springer Verlag, Chapter 3.2 “Immobilization” pp. 345-356.Immobilized enzymes are commercially available, for example fromNovozymes Biotech Inc., Denmark.

The amount of immobilized enzyme to be used is from 0.1 to 20% byweight, in particular from 10 to 15% by weight, based on the totalweight of the starting materials used and to be reacted.

The process using enzymes is carried out at temperatures above 60° C. Itis preferable to operate at temperatures of 100° C. or below thattemperature. Preference is given to temperatures up to 80° C., veryparticular preference is given to temperatures of from 62 to 75° C., andstill more preference is given to temperatures of from 65 to 75° C.

The process using enzymes is carried out in the presence of a solvent.Examples of suitable compounds are hydrocarbons, such as paraffins oraromatics. Particularly suitable paraffins are n-heptane andcyclohexane. Particularly suitable aromatics are toluene, ortho-xylene,meta-xylene, para-xylene, xylene in the form of an isomer mixture,ethylbenzene, chlorobenzene and ortho- and meta-dichlorobenzene. Othervery particularly suitable solvents are: ethers, such as dioxane ortetrahydrofuran, and ketones, such as methyl ethyl ketone and methylisobutyl ketone.

The amount of solvent added is at least 5 parts by weight, based on theweight of the starting materials used and to be reacted, preferably atleast 50 parts by weight, and particularly preferably at least 100 partsby weight. Amounts of more than 10 000 parts by weight of solvent areundesirable, because the reaction rate decreases markedly at markedlylower concentrations, giving uneconomically long reaction times.

The process using enzymes is carried out at pressures above 500 mbar.Preference is given to the reaction at atmospheric pressure or slightlyincreased pressure, for example at up to 1200 mbar. It is also possibleto operate under markedly increased pressure, for example at pressuresup to 10 bar. The reaction at atmospheric pressure is preferred.

The reaction time for the process using enzymes is usually from 4 hoursto 6 days, preferably from 5 hours to 5 days, and particularlypreferably from 8 hours to 4 days.

Once the reaction has ended, the highly functional hyperbranchedpolyesters can be isolated, e.g. by removing the enzyme by filtrationand concentrating the mixture, this concentration process usually beingcarried out at reduced pressure. Other work-up methods with goodsuitability are precipitation after addition of water, followed bywashing and drying.

The highly functional, hyperbranched polyesters B3) obtainable by thisenzyme-based process feature particularly low contents of discolouredand resinified material. For the definition of hyperbranched polymers,see also: P. J. Flory, J. Am. Chem. Soc. 1952, 74, 2718, and A. Sunderet al., Chem. Eur. J. 2000, 6, no. 1, 1-8. However, in the context ofthe present invention, “highly functional hyperbranched” means that thedegree of branching, i.e. the average number of dendritic linkages plusthe average number of end groups per molecule, is from 10 to 99.9%,preferably from 20 to 99%, particularly preferably from 30 to 90% (seein this connection H. Frey et al. Acta Polym. 1997, 48, 30).

The molar mass M_(w) of the polyesters B3) is from 500 to 50 000 g/mol,preferably from 1000 to 20 000 g/mol, particularly preferably from 1000to 19 000 g/mol. The polydispersity is from 1.2 to 50, preferably from1.4 to 40, particularly preferably from 1.5 to 30, and very particularlypreferably from 1.5 to 10. They are usually very soluble, i.e. clearsolutions can be prepared using up to 50% by weight, in some cases evenup to 80% by weight, of the polyesters B3) in tetrahydrofuran (THF),n-butyl acetate, ethanol, and numerous other solvents, with no gelparticles detectable by the naked eye.

The highly functional hyperbranched polyesters B3) arecarboxy-terminated, carboxy- and hydroxy-terminated orhydroxy-terminated, but preferably only hydroxy-terminated.

The hyperbranched polycarbonates B2)/polyesters B3) used are particleswhose size is from 20 to 500 nm. These nanoparticles are in finelydispersed form in the polymer blend, the size of the particles in thecompounded material being from 20 to 500 nm, preferably from 50 to 300nm.

Compounded materials of this type are available commercially, e.g. asUltradur® high speed.

The polyalkylene glycol esters (PAGE) B4) with low molecular weight, ofthe general formula (I)R—COO—(Z—O)_(n)OC—R  (I)in which

-   R is a branched or straight-chain alkyl group having from 1 to 20    carbon atoms,-   Z is a branched or straight-chain C₂ to C₁₅ alkylene group, and-   n is a whole number from 2 to 20,

can likewise be used as flow improvers, and are known from WO 98/11164A1. Particular preference is given to triethylene glycolbis(2-ethylhexanoate) (TEG-EH), marketed as TEG-EH-Plasticizer, CAS No.94-28-0, by Eastman Chemical B.V., The Hague, Netherlands.

If a mixture of B) components is used, the ratios of the components B1)to B2) or B2) to B3) or B1) to B3) or B1) to B4) or B2) to B4) or B3) toB4) are preferably from 1:20 to 20:1, in particular from 1:15 to 15:1and very particularly from 1:5 to 5:1. If a ternary mixture is usedcomposed of, for example, B1), B2) and B3), the mixing ratio ispreferably from 1:1:20 to 1:20:1 or up to 20:1:1. This applies likewiseto ternary mixtures using B4).

In one preferred embodiment, the present invention provides lightweightcomponents composed of a parent body composed of galvanized iron andhaving reinforcing structures, where the reinforcing structures havebeen securely connected to the parent body and are composed ofmoulded-on thermoplastic, characterized in that the thermoplastic usedcomprises polymer moulding compositions comprising

-   A) from 99.99 to 10 parts by weight, preferably from 99.5 to 40    parts by weight, particularly preferably from 99.0 to 55 parts by    weight, of polyamide and-   B1) from 0.01 to 50 parts by weight, preferably from 0.25 to 20    parts by weight, particularly preferably from 1.0 to 15 parts by    weight, of at least one copolymer composed of at least one olefin,    preferably of one α-olefin, with at least one methacrylate or    acrylate of an aliphatic alcohol, preferably of an aliphatic alcohol    having from 1 to 30 carbon atoms with MFI not less than 100 g/10    min, where the MFI (Melt Flow Index) is measured or determined at    190° C. with a test weight of 2.16 kg, and the secure interlock    connection between parent body and thermoplastic is achieved by way    of the galvanized surface of the parent body, and this surface has    additionally been pretreated by a process from the group of acid    treatment, soda treatment, amine treatment, anodic treatment, base    treatment or laser treatment.

In one particularly preferred embodiment, the present invention provideslightweight components obtainable from polymer moulding compositions ofcomponents A) and B1) whose parent body is of shell-type design, wherethe exterior or interior of the said body additionally has reinforcingstructures securely connected to the parent body and composed of thesame moulded-on thermoplastic, and, in one alternative embodiment, theconnection of these to the parent body is additionally achieved atdiscrete connection sites. These discrete connection sites canpreferably be perforations in the parent body, where the thermoplasticpasses through these perforations and extends over the area of theperforations, thus additionally reinforcing the secure interlockconnection which is in any case already being achieved by way of thegalvanized surface of the iron parent body. The reinforcing structuresare preferably of rib shape or of honeycomb shape.

In another preferred embodiment of the present invention, mouldingcompositions used for the lightweight components of hybrid design alsocomprise, in addition to components A) and, if appropriate, B),

-   C) from 0.001 to 75 parts by weight, preferably from 10 to 70 parts    by weight, particularly preferably from 20 to 65 parts by weight,    with particular preference from 30 to 65 parts by weight, of a    filler or reinforcing material.

The filler or reinforcing material used can also comprise a mixturecomposed of two or more different fillers and/or reinforcing materials,for example based on talc, or mica, silicate, quartz, titanium dioxide,wollastonite, kaolin, amorphous silicas, magnesium carbonate, chalk,feldspar, barium sulphate, glass beads and/or fibrous fillers and/orreinforcing materials based on carbon fibres and/or glass fibres. It ispreferable to use mineral particulate fillers based on talc, mica,silicate, quartz, titanium dioxide, wollastonite, kaolin, amorphoussilicas, magnesium carbonate, chalk, feldspar, barium sulphate and/orglass fibres. It is particularly preferable to use mineral particulatefillers based on talc, wollastonite, kaolin and/or glass fibres, veryparticular preference being given to glass fibres.

Particularly for applications in which isotropy in dimensional stabilityand high thermal dimensional stability is demanded, as for example inmotor vehicle applications for external bodywork parts, it is preferableto use mineral fillers, in particular talc, wollastonite or kaolin.

Particular preference is moreover also given to the use of acicularmineral fillers. According to the invention, the term acicular mineralfillers means a mineral filler having pronounced acicular character. Anexample that may be mentioned is acicular wollastonites. Thelength:diameter ratio of the mineral is preferably from 2:1 to 35:1,particularly preferably from 3:1 to 19:1, with particular preferencefrom 4:1 to 12:1. The average particle size, determined using a CILASGRANULOMETER, of the inventive acicular minerals is preferably smallerthan 20 μm, particularly preferably smaller than 15 μm, with particularpreference smaller than 10 μm.

The filler and/or reinforcing material can, if appropriate, have beensurface-modified, for example with a coupling agent or coupling-agentsystem, for example based on silane. However, this pre-treatment is notessential. However, in particular when glass fibres are used it is alsopossible to use polymer dispersions, film-formers, branching agentsand/or glass-fibre-processing aids, in addition to silanes.

The glass fibres whose use is particularly preferred according to theinvention are added in the form of continuous-filament fibres or in theform of chopped or ground glass fibres, their fibre diameter generallybeing from 7 to 18 μm, preferably from 9 to 15 μm. The fibres can havebeen provided with a suitable size system and with a coupling agent orcoupling-agent system, for example based on silane.

Coupling agents based on silane and commonly used for the pretreatmentprocess are silane compounds, preferably silane compounds of the generalformula (XIII)(X—(CH₂)_(q))_(k)—Si—(O—C_(r)H_(2r+1))_(4−k)  (XIII)in which

-   X is NH₂—, HO— or

-   q is a whole number from 2 to 10, preferably from 3 to 4,-   r is a whole number from 1 to 5, preferably from 1 to 2 and-   k is a whole number from 1 to 3, preferably 1.

Coupling agents to which further preference is given are silanecompounds from the group of aminopropyltrimethoxysilane,aminobutyltrimethoxysilane, aminopropyltriethoxysilane,aminobutyltriethoxysilane, and also the corresponding silanes which havea glycidyl group as substituent X.

The amounts generally used of the silane compounds for surface coatingfor modification of the fillers is from 0.05 to 2% by weight, preferablyfrom 0.25 to 1.5% by weight and in particular from 0.5 to 1% by weight,based on the mineral filler.

As a result of the processing to give the moulding composition ormoulding, the d97 value or d50 value of the particulate fillers can besmaller in the moulding composition or in the moulding than in thefillers originally used. As a result of the processing to give themoulding composition or moulding, the length distributions of the glassfibres in the moulding composition or the moulding can be shorter thanthose originally used.

In an alternative preferred embodiment, the polymer mouldingcompositions to be used for the production of the lightweight componentsof hybrid design according to the invention can also, if appropriate,comprise, in addition to components A) and, if appropriate, B) and/orC), or instead of B) and/or C),

-   D) from 0.001 to 30 parts by weight, preferably from 5 to 25 parts    by weight, particularly preferably from 9 to 19 parts by weight, of    at least one flame-retardant additive.

The flame-retardant additive or flame retardant D) used can comprisecommercially available organic halogen compounds with synergists or cancomprise commercially available organic nitrogen compounds ororganic/inorganic phosphorus compounds, individually or in a mixture. Itis also possible to use flame-retardant additives such as magnesiumhydroxide or Ca Mg carbonate hydrates (e.g. DE-A 4 236 122 (=CA 210 9024A1)). It is also possible to use salts of aliphatic or aromaticsulphonic acids. Examples that may be mentioned of halogen-containing,in particular brominated and chlorinated, compounds are:ethylene-1,2-bistetrabromophthalimide, epoxidized tetrabromobisphenol Aresin, tetrabromobisphenol A oligocarbonate, tetrachlorobisphenol Aoligo-carbonate, pentabromopolyacrylate, brominated polystyrene anddecabromodiphenyl ether. Examples of suitable organic phosphoruscompounds are the phosphorus compounds according to WO-A 98/17720 (=U.S.Pat. No. 6,538,024), e.g. triphenyl phosphate (TPP), resorcinolbis(diphenyl phosphate) (RDP) and the oligomers derived therefrom, andalso bisphenol A bis(diphenyl phosphate) (BDP) and the oligomers derivedtherefrom, and moreover organic and inorganic phosphonic acidderivatives and their salts, organic and inorganic phosphinic acidderivatives and their salts, in particular metal dialkylphosphinates,such as aluminium tris[dialkylphosphinates] or zincbis[dialkylphosphinates], and moreover red phosphorus, phosphites,hypophosphites, phosphine oxides, phosphazenes, melamine pyrophosphateand mixtures of these. Nitrogen compounds that can be used are thosefrom the group of the allantoin derivatives, cyanuric acid derivatives,dicyandiamide derivatives, glycoluril derivatives, guanidinederivatives, ammonium derivatives and melamine derivatives, preferablyallantoin, benzoguanamine, glycoluril, melamine, condensates ofmelamine, e.g. melem, melam or melom, or compounds of this type havinghigher condensation level and adducts of melamine with acids, e.g. withcyanuric acid (melamine cyanurate), with phosphoric acid (melaminephosphate) or with condensed phosphoric acids (e.g. melaminepolyphosphate). Examples of suitable synergists are antimony compounds,in particular antimony trioxide, sodium antimonate and antimonypentoxide, zinc compounds, e.g. zinc borate, zinc oxide, zinc phosphateand zinc sulphide, tin compounds, e.g. tin stannate and tin borate, andalso magnesium compounds, e.g. magnesium oxide, magnesium carbonate andmagnesium borate. Materials known as carbonizers can also be added tothe flame retardant, examples being phenol-formaldehyde resins,polycarbonates, polyphenyl ethers, polyimides, polysulphones, polyethersulphones, polyphenylene sulphides, and polyether ketones, and alsoantidrip agents, such as tetrafluoroethylene polymers.

In another alternative preferred embodiment, the polymer mouldingcompositions to be used for the production of the lightweight componentsof hybrid design according to the invention can also, if appropriate,comprise, in addition to components A) and, if appropriate, B) and C)and/or D), or instead of B) and/or C) and/or D),

-   E) from 0.001 to 80 parts by weight, particularly preferably from 2    to 19 parts by weight, with particular preference from 9 to 15 parts    by weight, of at least one elastomer modifier.

The elastomer modifiers to be used as component E) comprise one or moregraft polymers of

-   E.1 from 5 to 95% by weight, preferably from 30 to 90% by weight, of    at least one vinyl monomer on-   E.2 from 95 to 5% by weight, preferably from 70 to 10% by weight, of    one or more graft bases whose glass transition temperatures are <10°    C., preferably <0° C., particularly preferably <−20° C.

The average particle size (d₅₀ value) of the graft base E.2 is generallyfrom 0.05 to 10 μm, preferably from 0.1 to 5 μm, particularly preferablyfrom 0.2 to 1 μm.

Monomers E.1 are preferably mixtures composed of

-   E.1.1 from 50 to 99% by weight of vinylaromatics and/or    ring-substituted vinylaromatics (such as styrene, α-methylstyrene,    p-methylstyrene, p-chlorostyrene) and/or (C₁-C₈)-alkyl methacrylates    (e.g. methyl methacrylate, ethyl methacrylate) and-   E.1.2 from 1 to 50% by weight of vinyl cyanides (unsaturated    nitriles, such as acrylonitrile and methacrylonitrile) and/or    (C₁-C₈)-alkyl(meth)acrylates (e.g. methyl methacrylate, n-butyl    acrylate, tert-butyl acrylate) and/or derivatives (such as    anhydrides and imides) of unsaturated carboxylic acids (e.g. maleic    anhydride and N-phenylmaleimide).

Preferred monomers E.1.1 have been selected from at least one of themonomers styrene, α-methylstyrene and methyl methacrylate, and preferredmonomers E.1.2 have been selected from at least one of the monomersacrylonitrile, maleic anhydride and methyl methacrylate.

Particularly preferred monomers are E.1.1 styrene and E.1.2acrylonitrile.

Examples of suitable graft bases E.2 for the graft polymers to be usedin the elastomer modifiers E) are diene rubbers, EP(D)M rubbers, i.e.rubbers based on ethylene/propylene and, if appropriate, diene, acrylaterubbers, polyurethane rubbers, silicone rubbers, chloroprene rubbers andethylene-vinyl acetate rubbers.

Preferred graft bases E.2 are diene rubbers (e.g. based on butadiene,isoprene, etc.) or mixtures of diene rubbers, or are copolymers of dienerubbers or of their mixtures with further copolymerizable monomers (e.g.according to E.1.1 and E.1.2), with the proviso that the glasstransition temperature of component E.2 is <10° C., preferably <0° C.,particularly preferably <−10° C.

Examples of particularly preferred graft bases E.2 are ABS polymers(emulsion, bulk and suspension ABS), as described by way of example inDE-A 2 035 390 (=U.S. Pat. No. 3,644,574) or in DE-A 2 248 242 (=GB-A 1409 275) or in Ullmann, Enzyklopädie der Technischen Chemie[Encyclopaedia of Industrial Chemistry], Vol. 19 (1980), pp. 280 et seq.The gel content of the graft base E.2 is preferably at least 30% byweight, particularly preferably at least 40% by weight (measured intoluene).

The elastomer modifiers or graft polymers E) are prepared viafree-radical polymerization, e.g. via emulsion, suspension, solution orbulk polymerization, preferably via emulsion or bulk polymerization.

Other particularly suitable graft rubbers are ABS polymers which areprepared via redox initiation using an initiator system composed oforganic hydroperoxide and ascorbic acid according to U.S. Pat. No.4,937,285.

Because it is known that the graft monomers are not necessarily entirelygrafted onto the graft base during the grafting reaction, products whichare obtained via (co)polymerization of the graft monomers in thepresence of the graft base and are produced concomitantly during thework-up are also graft polymers E) according to the invention.

Suitable acrylate rubbers are based on graft bases E.2 which arepreferably polymers composed of alkyl acrylates, if appropriate with upto 40% by weight, based on E.2, of other polymerizable, ethylenicallyunsaturated monomers. Among the preferred polymerizable acrylic estersare C₁-C₈-alkyl esters, such as methyl, ethyl, butyl, n-octyl and2-ethylhexyl esters; haloalkyl esters, preferably halo-C₁-C₈-alkylesters, such as chloroethyl acrylate, and also mixtures of thesemonomers.

For crosslinking, monomers having more than one polymerizable doublebond can be copolymerized. Preferred examples of crosslinking monomersare esters of unsaturated monocarboxylic acids having from 3 to 8 carbonatoms and esters of unsaturated monohydric alcohols having from 3 to 12carbon atoms, or of saturated polyols having from 2 to 4 OH groups andfrom 2 to 20 carbon atoms, e.g. ethylene glycol dimethacrylate, allylmethacrylate; polyunsaturated heterocyclic compounds, e.g. trivinyl andtriallyl cyanurate; polyfunctional vinyl compounds, such as di- andtrivinylbenzenes; and also triallyl phosphate and diallyl phthalate.

Preferred crosslinking monomers are allyl methacrylate, ethylene glycoldimethacrylate, diallyl phthalate and heterocyclic compounds which haveat least 3 ethylenically unsaturated groups.

Particularly preferred crosslinking monomers are the cyclic monomerstriallyl cyanurate, triallyl isocyanurate,triacryloylhexahydro-s-triazine, and triallylbenzenes. The amount of thecrosslinking monomers is preferably from 0.02 to 5% by weight, inparticular from 0.05 to 2% by weight, based on the graft base E.2.

In the case of cyclic crosslinking monomers having at least 3ethylenically unsaturated groups, it is advantageous to restrict theamount to below 1% by weight of the graft base E.2.

Examples of preferred “other” polymerizable, ethylenically unsaturatedmonomers which can serve alongside the acrylic esters, if appropriate,for preparation of the graft base E.2 are acrylonitrile, styrene,α-methylstyrene, acrylamides, vinyl C₁-C₆-alkyl ethers, methylmethacrylate, butadiene. Acrylate rubbers preferred as graft base E.2are emulsion polymers whose gel content is at least 60% by weight.

Further suitable graft bases according to E.2 are silicone rubbershaving sites active for grafting purposes, as described in DE-A 3 704657 (=U.S. Pat. No. 4,859,740), DE-A 3 704 655 (=U.S. Pat. No.4,861,831), DE-A 3 631 540 (=U.S. Pat. No. 4,806,593) and DE-A 3 631 539(=U.S. Pat. No. 4,812,515).

Alongside elastomer modifiers based on graft polymers, it is alsopossible to use, as component E), elastomer modifiers not based on graftpolymers but having glass transition temperatures <10° C., preferably<0° C., particularly preferably <−20° C. Among these can be, by way ofexample, elastomers with block copolymer structure. Among these can alsobe, by way of example, elastomers which can undergo thermoplasticmelting. Preferred materials mentioned here by way of example are EPMrubbers, EPDM rubbers and/or SEBS rubbers.

In another alternative preferred embodiment, the polymer mouldingcompositions to be used for the production of the lightweight componentsof hybrid design according to the invention can also, if appropriate,comprise, in addition to components A) and, if appropriate, B) and/or C)and/or D) and/or E), or instead of B), C), D) or E),

-   F) from 0.001 to 10 parts by weight, preferably from 0.05 to 3 parts    by weight, particularly preferably from 0.1 to 0.9 part by weight,    of further conventional additives.

For the purposes of the present invention, examples of conventionaladditives are stabilizers (e.g. UV stabilizers, heat stabilizers,gamma-ray stabilizers), antistatic agents, flow aids, mould-releaseagents, further fire-protection additives, emulsifiers, nucleatingagents, plasticizers, lubricants, dyes, pigments and additives forincreasing electrical conductivity. The additives mentioned and furthersuitable additives are described by way of example in Gächter, Müller,Kunststoff-Additive [Plastics Additives], 3rd Edition, Hanser-Verlag,Munich, Vienna, 1989 and in Plastics Additives Handbook, 5th Edition,Hanser-Verlag, Munich, 2001. The additives may be used alone or in amixture, or in the form of masterbatches.

Preferred stabilizers used are sterically hindered phenols,hydroquinones, aromatic secondary amines, e.g. diphenylamines,substituted resorcinols, salicylates, benzotriazoles and benzophenones,and also various substituted representatives of these groups andmixtures thereof.

Preferred pigments and dyes used are titanium dioxide, zinc sulphide,ultramarine blue, iron oxide, carbon black, phthalocyanines,quinacridones, perylenes, nigrosin and anthraquinones.

Preferred nucleating agents used are sodium phenylphosphinate or calciumphenylphosphinate, aluminium oxide, silicon dioxide, or else talc,particularly preferably talc.

Preferred lubricants and mould-release agents used are ester waxes,pentaerythritol tetrastearate (PETS), long-chain fatty acids (e.g.stearic acid or behenic acid) and fatty acid esters, salts thereof (e.g.Ca stearate or Zn stearate), and also amide derivatives (e.g.ethylenebisstearylamide) or montan waxes (mixtures composed ofstraight-chain, saturated carboxylic acids having chain lengths of from28 to 32 carbon atoms), and also low-molecular-weight polyethylene waxesand polypropylene waxes.

Preferred plasticizers used are dioctyl phthalate, dibenzyl phthalate,butyl benzyl phthalate, hydrocarbon oils,N-(n-butyl)benzenesulphonamide.

Preferred additives which can be added to increase electricalconductivity are carbon blacks, conductivity blacks, carbon fibrils,nanoscale graphite fibres and carbon fibres, graphite, conductivepolymers, metal fibres, and also other conventional additives forincreasing electrical conductivity. Nanoscale fibres which canpreferably be used are those known as “single-wall carbon nanotubes” or“multiwall carbon nanotubes” (e.g. from Hyperion Catalysis).

In another alternative preferred embodiment, the polyamide mouldingcompositions can also, if appropriate, comprise, in addition tocomponents A) and, if appropriate, B) and/or C), and/or D), and/or E),and/or F), or instead of B), C), D), E) or F),

-   G) from 0.5 to 30 parts by weight, preferably from 1 to 20 parts by    weight, particularly preferably from 2 to 10 parts by weight and    most preferably from 3 to 7 parts by weight, of compatibilizer.

Compatibilizers used preferably comprise thermoplastic polymers havingpolar groups.

According to the invention, polymers which can be used are thereforethose which contain

-   -   G.1 a vinylaromatic monomer,    -   G.2 at least one monomer selected from the group of C₂-C₁₂-alkyl        methacrylates, C₂-C₁₂-alkyl acrylates, methacrylonitriles and        acrylonitriles and    -   G.3 dicarboxylic anhydrides containing α,β-unsaturated        components.

The component used composed of G.1, G.2 and G.3 preferably comprisesterpolymers of the monomers mentioned. Accordingly, it is preferable touse terpolymers of styrene, acrylonitrile and maleic anhydride. Inparticular, these terpolymers contribute to improvement in mechanicalproperties, such as tensile strength and tensile strain at break. Theamount of maleic anhydride in the terpolymer can vary widely. The amountis preferably from 0.2 to 5 mol %. Amounts of from 0.5 to 1.5 mol % areparticularly preferred. In this range, particularly good mechanicalproperties are achieved in relation to tensile strength and tensilestrain at break.

The terpolymer can be prepared in a known manner. One suitable method isto dissolve monomer components of the terpolymer, e.g. styrene, maleicanhydride or acrylonitrile, in a suitable solvent, e.g. methyl ethylketone (MEK). One or, if appropriate, more chemical initiators are addedto this solution. Preferred initiators are peroxides. The mixture isthen polymerized at elevated temperatures for a number of hours. Thesolvent and the unreacted monomers are then removed in a manner knownper se.

The ratio of component G.1 (vinylaromatic monomer) to component G.2,e.g. the acrylonitrile monomer in the terpolymer is preferably from80:20 to 50:50.

Styrene is particularly preferred as vinylaromatic monomer G.1.Acrylonitrile is particularly preferably suitable for component G.2.Maleic anhydride is particularly preferably suitable as component G.3.

EP-A 0 785 234 (=U.S. Pat. No. 5,756,576) and EP-A 0 202 214 (=U.S. Pat.No. 4,713,415) describe examples of compatibilizers G) which can be usedaccording to the invention. According to the invention, particularpreference is given to the polymers mentioned in EP-A 0 785 234.

The compatibilizers can be present in component G) alone or in anydesired mixture with one another.

Another substance particularly preferred as compatibilizer is aterpolymer of styrene and acyrlonitrile in a ratio of 2.1:1 by weightcontaining 1 mol % of maleic anhydride.

Component G) is used particularly when the moulding compositioncomprises graft polymers, as described under E).

According to the invention, the following combinations of the componentsare preferred in polymer moulding compositions for use in hybrid-basedlightweight components:

A; A,B; A,B,C; A,B,D; A,B,E; A,B,F; A,B,G; A,B,C,D; A,B,C,E; A,B,C,F;A,B,C,G; A,B,D,E; A,B,D,F; A,B,D,G; A,B,E,F; A,B,E,G; A,B,F,G;A,B,C,D,E; A,B,C,D,G; A,B,C,F,G; A,B,E,F,G; A,B,D,F,G; A,B,C,D,E,F;A,B,C,D,E,G; A,B,D,E,F,G; A,B,C,E,F,G; A,B,C,D,E,G; A,B,C,D,E,F,G.

The lightweight components of hybrid design to be produced according tothe invention from the polymer moulding compositions used feature anexceptionally secure connection of the galvanized iron parent body tothe thermoplastic. They also have high impact resistance and anunusually high modulus of elasticity of about 19 000 MPa at roomtemperature. In the event that polyamide is used in combination, forexample, with a component B1), the content of glass fibres can bedoubled from 30% by weight to 60% by weight, leading to doubledstiffness of a lightweight component of hybrid design producedtherefrom. Surprisingly, the density of the polymer moulding compositionincreases by only about 15-20% here. This permits a significantreduction of the wall thicknesses of the components for the samemechanical performance, with markedly reduced manufacturing costs.Motor-vehicle front ends, a standard application of hybrid technology,can thus be designed to be lighter and/or stiffer, and this is attendedby a reduction of 30-40% in weight and in manufacturing costs, incomparison with a component manufactured conventionally.

Lightweight components of hybrid design to be produced according to theinvention using flow improver B) and composed of a galvanized ironparent body whose exterior or interior, in the event of use of ashell-type parent body, has reinforcing structures, preferably in theform of ribs, securely connected to the parent body and composed ofmoulded-on thermoplastic, where the connection of these to the parentbody is achieved at discrete connection sites by way of perforations inthe parent body can therefore be used in the automotive andnon-automotive sectors, preferably as vehicle parts (automotive sector),in load-bearing parts of office machinery, household machines or othermachinery, in design elements for decorative purposes, in staircases, inescalator steps, or in manhole covers.

They are preferably used in motor vehicles as roof structures, composedby way of example of roof frames, roof arch and/or rooftop elements, orfor column structures, e.g. A-, B- and/or C-column, for chassisstructures, composed by way of example of steering stub, coupling rod,wishbone and/or stabilizers, or for longitudinal-member structures, forexample composed of longitudinal member and/or door sill, or forfront-end structures, for example composed of front ends, front-endmodule, headlamp frame, lock member, transverse member, radiator memberand/or assembly support, or for pedal structures, for example composedof brake pedal, accelerator pedal and clutch pedal, pedal block and/orpedal module, or for door structures and flap structures, for examplefront and rear driver and passenger doors, tailgates and/or engine hood,or for instrument-panel-support structures, for example composed oftransverse member, instrument-panel member and/or cockpit member, foroil sumps, for example transmission-oil sumps and/or oil modules, or forseat structures, for example composed of seat-backrest structure,backrest structure, seat-pan structure, belt cross-tie and/or arm rests,or in the form of complete front ends, pedestrian-protection beam,specialized slam panels for engine hoods or luggage-compartment lids,front roof arch, rear roof arch, roof frame, roof modules (entire roof),sliding-roof-support parts, dashboard support parts (cross car beam),steering-column retainers, firewall, pedals, pedal blocks, gear-shiftblocks, A-columns, B-columns, or C-columns, B-column modules,longitudinal members, jointing elements for the connection oflongitudinal members and B-columns, jointing elements for the connectionof A-column and transverse member, jointing elements for the connectionof A-column, transverse member and longitudinal member, transversemembers, wheel surrounds, wheel-surround modules, crash boxes, rearends, spare-wheel recesses, engine hoods, engine covers, water-tankassembly, engine-rigidity systems (front-end rigidity system), vehiclefloor, floor-rigidity systems, seat-rigidity system, transverse seatmembers, tailgates, vehicle frames, seat structures, back-rests, seatshells, seat back-rests with or without safety-belt integration, parcelshelves, valve covers, end-shields for generators or electric motors,complete vehicle-door structures, side-impact members, module members,oil sumps, gearbox-oil sumps, oil modules, headlamp frames, door sills,door-sill reinforcement, chassis components and motor-scooter frames.

In the non-automotive sector, the lightweight components of hybriddesign according to the invention are preferably used in electrical andelectronics equipment, household equipment, furniture, heaters, shoppingtrolleys, shelving, staircases, escalator steps, or manhole covers.

However, the lightweight components of hybrid design according to theinvention are, of course, also suitable for use in rail vehicles,aircraft, ships, sleds, motor scooters or other means of conveyance,where lightweight but stable designs are important.

However, the present invention also provides a process for theproduction of a lightweight component of hybrid design composed of aparent body which has reinforcing structures and which is composed ofgalvanized iron, where the reinforcing structures have been securelyconnected to the parent body and are composed of moulded-onthermoplastic, characterized in that the thermoplastic used comprisespolymer moulding compositions based on polyamide, and these comprisefrom 99.99 to 10 parts by weight, preferably from 99.5 to 40 parts byweight, particularly preferably from 99.0 to 55 parts by weight, of atleast one aliphatic, semicrystalline, thermoplastic polyamide, and thesecure interlock connection between parent body and thermoplastic isachieved by shaping processes in a shaping mould, by way of thegalvanized iron surface of the parent body.

In one preferred embodiment, the present invention provides a processfor the production of a lightweight component of hybrid design composedof a parent body which has reinforcing structures and which is composedof galvanized iron, where the reinforcing structures have been securelyconnected to the parent body and are composed of moulded-onthermoplastic, characterized in that the polyamides to be used comprisenylon-6 (PA 6) or nylon-6,6 (PA 66) with relative solution viscositiesof from 2.0 to 4.0 (measured in m-cresol at 25° C.), and particularlypreferably nylon-6 with a relative solution viscosity of from 2.3 to 2.6(measured in m-cresol at 25° C.), or a mixture composed of

-   A) from 99.99 to 10 parts by weight, preferably from 99.5 to 40    parts by weight, particularly preferably from 99.0 to 55 parts by    weight, of polyamide, with at least one component B) from 0.01 to 50    parts by weight, preferably from 0.25 to 20 parts by weight,    particularly preferably from 1.0 to 15 parts by weight, of an    additional flow improver from the group of-   B1) a copolymer composed of at least one olefin, preferably an    α-olefin, with at least one methacrylate or acrylate of an aliphatic    alcohol, preferably of an aliphatic alcohol having from 1 to 30    carbon atoms, with MFI of not less than 100 g/10 min, the MFI (melt    flow index) being measured or determined at 190° C. using a test    weight of 2.16 kg, or-   B2) a highly branched or hyperbranched polycarbonate with an OH    number of from 1 to 600 mg KOH/g of polycarbonate (to DIN 53240,    Part 2), or-   B3) a highly branched or hyperbranched polyester of A_(x)B_(y) type,    where x is at least 1.1 and y is at least 2.1, or-   B4) a polyalkylene glycol ester (PAGE) with low molecular weight of    the general formula (I)    R—COO—(Z—O)_(n)OC—R  (I)    -   in which    -   R is a branched or straight-chain alkyl group having from 1 to        20 carbon atoms,    -   Z is a branched or straight-chain C₂ to C₁₅ alkylene group, and    -   n is a whole number from 2 to 20, or        a mixture of B1) with B2) or of B2) with B3) or of B1) with B3)        or of B1) with B2) and with B3) or of B1) with B4) or of B2)        with B4) or of B3) with B4) or a ternary mixture of components        B1) to B4), in each case with A), where the secure interlock        connection between parent body and thermoplastic is achieved by        way of the galvanized iron surface of the parent body, and the        secure interlock connection between parent body and        thermoplastic is achieved by way of the galvanized surface of        the parent body, after pretreatment by a process from the group        of acid treatment, soda treatment, amine treatment, anodic        treatment, base treatment or laser treatment, by shaping        processes in a shaping mould.

However, the present invention also provides a method for reducing theweight of components, preferably of vehicles of any type, characterizedin that

lightweight components of hybrid design composed of a parent body whichhas reinforcing structures and which is composed of galvanized iron, thesurface of which has been pretreated by a process from the group of acidtreatment, soda treatment, amine treatment, anodic treatment, basetreatment or laser treatment, where the reinforcing structures have beensecurely connected to the parent body and are composed of moulded-onthermoplastic, and the thermoplastic used comprises mouldingcompositions comprising from 99.99 to 10 parts by weight, preferablyfrom 99.5 to 40 parts by weight, particularly preferably from 99.0 to 55parts by weight, of at least one aliphatic, semicrystalline,thermoplastic polyamide.

In one preferred embodiment, the present invention provides a method forreducing the weight of components, preferably of vehicles of any type,characterized in that lightweight components of hybrid design composedof a parent body which has reinforcing structures and which is composedof galvanized iron, the surface of which has been pretreated by aprocess from the group of acid treatment, soda treatment, aminetreatment, anodic treatment, base treatment or laser treatment, wherethe reinforcing structures have been securely connected to the parentbody and are composed of moulded-on thermoplastic, and the thermoplasticused comprises moulding compositions comprising polyamide, preferablynylon-6 (PA 6) or nylon-6,6 (PA 66) with relative solution viscositiesof from 2.0 to 4.0 (measured in m-cresol at 25° C.), and particularlypreferably nylon-6 with a relative solution viscosity of from 2.3 to 2.6(measured in m-cresol at 25° C.), or a mixture composed of

-   A) from 99.99 to 10 parts by weight, preferably from 99.5 to 40    parts by weight, particularly preferably from 99.0 to 55 parts by    weight, of polyamide, with at least one component B) from 0.01 to 50    parts by weight, preferably from 0.25 to 20 parts by weight,    particularly preferably from 1.0 to 15 parts by weight, of a flow    improver from the group of-   B1) a copolymer composed of at least one olefin, preferably an    α-olefin, with at least one methacrylate or acrylate of an aliphatic    alcohol, preferably of an aliphatic alcohol having from 1 to 30    carbon atoms, with MFI of not less than 100 g/10 min, the MFI (melt    flow index) being measured or determined at 190° C. using a test    weight of 2.16 kg, or-   B2) a highly branched or hyperbranched polycarbonate with an OH    number of from 1 to 600 mg KOH/g of polycarbonate (to DIN 53240,    Part 2), or-   B3) a highly branched or hyperbranched polyester of A_(x)B_(y) type,    where x is at least 1.1 and y is at least 2.1, or-   B4) a polyalkylene glycol ester (PAGE) with low molecular weight of    the general formula (I)    R—COO—(Z—O)_(n)OC—R  (I)    -   in which    -   R is a branched or straight-chain alkyl group having from 1 to        20 carbon atoms,    -   Z is a branched or straight-chain C₂ to C₁₅ alkylene group, and    -   n is a whole number from 2 to 20, or        a mixture of B1) with B2) or of B2) with B3) or of B1) with B3)        or of B1) with B2) and with B3) or of B1) with B4) or of B2)        with B4) or of B3) with B4) or a ternary mixture of components        B1) to B4), in each case with A), where the secure interlock        connection between parent body and thermoplastic is achieved by        way of the galvanized iron surface of the parent body.

For the purposes of the present invention, a secure interlock connectionmeans that the extruded polymer is securely connected to the galvanizediron parent body by way of microstructures in the surface of the same,and that there is no free movement within the said secure interlockconnection, and that the cross section of the interlock connection hasto be disrupted under load before the connected subsections composedfirstly of metal and secondly of injected thermoplastic can be separatedfrom one another.

In one preferred embodiment, the said interlock connection is alsopromoted or enhanced by openings in the parent body, in that thethermoplastic is forced through these and flows out on the opposite sideof the openings by way of the edges of the openings, thus giving asecure interlock connection on solidification. In one particularlypreferred embodiment it is also possible, however that the flashmaterial protruding by way of the openings is subjected to mechanicalworking with a tool in an additional operation, in such a way as toprovide further enhancement of the interlock connection. In anothermeaning of the term “securely connected”, (an) item(s) is/aresubsequently bonded in place by use of adhesives or by use of a laser.However, it is also possible to achieve the secure interlock connectionby a process involving flow around (producing a web around) the parentbody.

However, the present invention also provides vehicles or other means ofconveyance, preferably motor vehicles, rail vehicles, aircrafts, ships,sleds or motor scooters, comprising a lightweight component of hybriddesign composed of a parent body composed of galvanized iron withmoulded-on thermoplastic, characterized in that the polymer mouldingcompositions used comprise polyamide as thermoplastic, and the saidlightweight component is installed within the vehicle.

The present invention preferably provides vehicles or other means ofconveyance, characterized in that the thermoplastic used for thelightweight component comprises nylon-6 (PA 6) or nylon-6,6 (PA 66) withrelative solution viscosities of from 2.0 to 4.0 (measured in m-cresolat 25° C.), and particularly preferably nylon-6 with a relative solutionviscosity of from 2.3 to 2.6 (measured in m-cresol at 25° C.), or amixture composed of

-   A) from 99.99 to 10 parts by weight, preferably from 99.5 to 40    parts by weight, particularly preferably from 99.0 to 55 parts by    weight, of polyamide, with at least one component B) from 0.01 to 50    parts by weight, preferably from 0.25 to 20 parts by weight,    particularly preferably from 1.0 to 15 parts by weight, of an    additional flow improver from the group of-   B1) a copolymer composed of at least one olefin, preferably an    α-olefin, with at least one methacrylate or acrylate of an aliphatic    alcohol, preferably of an aliphatic alcohol having from 1 to 30    carbon atoms, with MFI of not less than 100 g/10 min, the MFI (melt    flow index) being measured or determined at 190° C. using a test    weight of 2.16 kg, or-   B2) a highly branched or hyperbranched polycarbonate with an OH    number of from 1 to 600 mg KOH/g of polycarbonate (to DIN 53240,    Part 2), or-   B3) a highly branched or hyperbranched polyester of A_(x)B_(y) type,    where x is at least 1.1 and y is at least 2.1, or-   B4) a polyalkylene glycol ester (PAGE) with low molecular weight of    the general formula (I)    R—COO—(Z—O)_(n)OC—R  (I)    -   in which    -   R is a branched or straight-chain alkyl group having from 1 to        20 carbon atoms,    -   Z is a branched or straight-chain C₂ to C₁₅ alkylene group, and    -   n is a whole number from 2 to 20, or        a mixture of B1) with B2) or of B2) with B3) or of B1) with B3)        or of B1) with B2) and with B3) or of B1) with B4) or of B2)        with B4) or of B3) with B4) or a ternary mixture of components        B1) to B4), in each case with A), where the secure interlock        connection between parent body and thermoplastic is achieved by        way of the galvanized iron surface of the parent body, the        surface of which has been pretreated by a process from the group        of acid treatment, soda treatment, amine treatment, anodic        treatment, base treatment or laser treatment, and this        lightweight component is installed within the vehicle.

It will be understood that the specification and examples areillustrative but not limitative of the present invention and that otherembodiments within the spirit and scope of the invention will suggestthemselves to those skilled in the art.

EXAMPLES

Lightweight components to be produced according to the invention andbased on a parent body composed of galvanized iron sheet were producedusing

-   a) linear nylon-6 (Durethan® B29, product commercially available    from Lanxess Deutschland GmbH, Leverkusen, Germany) with a relative    solution viscosity of 2.9 (measured in m-cresol at 25° C.)-   b) linear nylon-6 (Durethan® B24, product commercially available    from Lanxess Deutschland GmbH, Leverkusen, Germany) with a relative    solution viscosity of 2.4 (measured in m-cresol at 25° C.)-   c) linear nylon-6,6 (Radipol® A45H, product commercially available    from Radici, Italy) with a relative solution viscosity of 3.0    (measured in m-cresol at 25° C.).

FIG. 1 shows a roof structure according to the invention, in which a aresheet metal profiles with moulded-on rib structure.

FIG. 2 shows a column structure according to the invention for avehicle, in which A is the A-column, B is the B-column and C is theC-column.

FIG. 3 shows a B-column (B) according to the invention, the inner metalsheet of which has been reinforced with moulded-on plastic in a ribstructure. X indicates possible spot weld positions.

FIG. 4 shows a door sill structure according to the invention for amotor vehicle with Y longitudinal member at the front and Z longitudinalmember at the rear. A indicates a section shown in FIG. 5.

FIG. 5 shows a door sill according to FIG. 4 in the form of a sectionaldetail A-A, in which i is a welded connection, j is the exterior metalsheet of the door sill and k is the interior metal sheet of the doorsill, 1 is the underbody metal sheet of a motor vehicle and m is aplastics rib structure moulded onto the interior metal sheet of the doorsill.

FIG. 6 shows an oil sump of a motor vehicle with a′ moulded-on flangeswith holes for screw threads and with peripheral sealing groove, b′moulded-on plastics ribs on the metal sheet, and c′ a moulded-on screwthread for screw fixtures for oil-discharge.

FIG. 7 shows a chassis structure according to the invention with d′ ametal sheet, e′ being a stabilizer insert using moulded-on-plasticsgeometry, on the metal sheet.

FIG. 8 shows three front-end structures according to the invention,composed of sheet-metal profiles overmoulded with plastic. The ribstructure of the plastics parts is clearly discernible.

FIG. 9 shows an instrument-panel-support structure according to theinvention, in which f′ is a closed sheet-metal profile with moulded-onretainers and fastening points.

FIG. 10 shows an open-shell sheet-metal profile according to theinvention for an instrument-panel support or CCB with moulded-onretainers and fastening points.

FIG. 11 shows an internal door structure (sheet-metal shell) accordingto the invention, with g′ moulded-on rib structure and fastening points.

FIG. 12 shows pedal structures for a motor vehicle.

FIG. 13 shows seat structures according to the invention, in which h′ isa sheet-metal profile to be inserted and i′ is a plastics-geometry/ribstructure to be moulded on.

1. A lightweight component comprised of a parent body of galvanized ironand having reinforcing structures, where the reinforcing structures aresecurely connected to the parent body and are formed of moulded-onthermoplastic polymer compositions, wherein the thermoplastic polymercompositions comprise polyamide moulding compositions which comprisefrom 99.99 to 10 parts by weight of at least one aliphatic,semicrystalline, thermoplastic polyamide, and the galvanized iron ispretreated by a process selected from the group consisting of acidtreatment, soda treatment, amine treatment, anodic treatment, basetreatment and laser treatment.
 2. A lightweight component according toclaim 1, wherein the secure connection between moulded-on thermoplasticand the parent body is further achieved by way of discrete connectionsites by way of perforations in the parent body, where the thermoplasticextends through these and across the area of the perforations.
 3. Alightweight component according to claim 1, wherein the parent body isof shell-type shape.
 4. A lightweight component according to claim 1,wherein the thermoplastic comprises polymer moulding compositionscomprising nylon-6 (PA 6) or nylon-6,6 (PA 66) with relative solutionviscosities of from 2.0 to 4.0 (measured in m-cresol at 25° C.) or amixture of A) from 99.99 to 10 parts by weight of polyamide and B) from0.01 to 50 parts by weight of B1) at least one copolymer of at least oneolefin with at least one methacrylate or acrylate of an aliphaticalcohol with MFI (melt flow index) of not less than 100 g/10 min, theMFI being measured or determined at 190° C. using a load of 2.16 kg, orB2) at least one highly branched or hyperbranched polycarbonate with anOH number of from 1 to 600 mg KOH/g of polycarbonate (to DIN 53240, Part2), or B3) at least one highly branched or hyperbranched polyester ofA_(x)B_(y) type, where x is at least 1.1 and y is at least 2.1, or B4)of at least one polyalkylene glycol ester (PAGE) with low molecularweight of the formula (I)R—COO—(Z—O)_(n)OC—R  (I) in which R is a branched or straight-chainalkyl group having from 1 to 20 carbon atoms, Z is a branched orstraight-chain C₂ to C₁₅ alkylene group, and n is a whole number from 2to 20, or a mixture of B1) with B2) or of B2) with B3) or of B1) withB3) or of B1) with B2) and with B3) or of B1) with B4) or of B2) withB4) or of B3) with B4) or a ternary mixture of components B1) to B4), ineach case with A).
 5. A lightweight component according to claim 4,wherein the moulding compositions comprise, in addition to components A)and B), C) from 0.001 to 75 parts by weight of a filler or reinforcingmaterial.
 6. A lightweight component according to claim 5, wherein thefiller or reinforcing material comprises glass fibres.
 7. A lightweightcomponent according to claim 1, wherein said moulding compositionscomprise polyamides containing macromolecular chains having astar-shaped structure and containing linear macromolecular chains.
 8. Alightweight component according to claim 7, wherein the polyamides areobtained by polymerizing a mixture of monomers comprising at least a)monomers of the formula (II) R₁-(-A-Z)_(m), b) monomers of the formula(IIIa) X—R₂—Y and (IIIb) R₂—NH—C═O c) monomers of the formula (IV)Z—R₃—Z, in which R₁ is a linear or cyclic, aromatic or aliphatichydrocarbon radical which contains at least two carbon atoms and whichcan contain heteroatoms, A is a covalent bond or an aliphatichydrocarbon radical having from 1 to 6 carbon atoms, Z is a primaryamine radical or a carboxy group, R₂ and R₃ are identical or differentaliphatic, cycloaliphatic or aromatic, substituted or unsubstitutedhydrocarbon radicals which contain from 2 to 20 carbon atoms and whichoptionally contain heteroatoms, and Y is a primary amine radical, if Xis a carbonyl radical, or Y is a carbonyl radical, if X is a primaryamine radical, where m is a whole number from 3 to
 8. 9. A process forthe production of a lightweight component of hybrid design composed of aparent body which has reinforcing structures and which is composed ofgalvanized iron, where the reinforcing structures are securely connectedto the parent body and are formed of moulded-on thermoplastic, whereinthe thermoplastic comprises polymer moulding compositions of polyamide,and these comprise from 99.99 to 10 parts by weight of at least onealiphatic, semicrystalline, thermoplastic polyamide, and secureinterlock connections are formed between parent body and thethermoplastic reinforcing structures by shaping processes in a shapingmould, by way of the galvanized iron surface of the parent body, thesurface of which has been pretreated by a process selected from thegroup consisting of acid treatment, soda treatment, amine treatment,anodic treatment, base treatment and laser treatment.
 10. A processaccording to claim 9, wherein the thermoplastic comprises polymermoulding compositions of nylon-6 (PA 6) or nylon-6,6 (PA 66) withrelative solution viscosities of from 2.0 to 4.0 (measured in m-cresolat 25° C.) or a mixture of A) from 99.99 to 10 parts by weight ofpolyamide and B) from 0.01 to 50 parts by weight, of: B1) at least onecopolymer of at least one olefin with at least one methacrylate oracrylate of an aliphatic alcohol with MFI (melt flow index) of not lessthan 100 g/10 min, the MFI being measured or determined at 190° C. usinga load of 2.16 kg, or B2) of at least one highly branched orhyperbranched polycarbonate with an OH number of from 1 to 600 mg KOH/gof polycarbonate (to DIN 53240, Part 2), or B3) of at least one highlybranched or hyperbranched polyester of A_(x)B_(y) type, where x is atleast 1.1 and y is at least 2.1, or B4) of at least one polyalkyleneglycol ester (PAGE) with low molecular weight of the formula (I)R—COO—(Z—O)_(n)OC—R  (I) in which R is a branched or straight-chainalkyl group having from 1 to 20 carbon atoms, Z is a branched orstraight-chain C₂ to C₁₅ alkylene group, and n is a whole number from 2to 20, or a mixture of B1) with B2) or of B2) with B3) or of B1) withB3) or of B1) with B2) and with B3) or of B1) with B4) or of B2) withB4) or of B3) with B4) or a ternary mixture of components B1) to B4), ineach case with A).
 11. Motor vehicles, rail vehicles, aircraft, ships,sleds or motor scooters, comprising a lightweight component of hybriddesign formed of a parent body of galvanized iron with moulded-onthermoplastic, wherein the thermoplastic is polyamide.
 12. Motorvehicles, rail vehicles, aircraft, ships, sleds or motor scootersaccording to claim 11, wherein said thermoplastic comprises nylon-6 (PA6) or nylon-6,6 (PA 66) with relative solution viscosities of from 2.0to 4.0 (measured in m-cresol at 25° C.) or a mixture of A) from 99.99 to10 parts by weight of polyamide and at least one component B) from 0.01to 50 parts by weight of an additional flow improver selected from thegroup consisting of B1) a copolymer of at least one olefin with at leastone methacrylate or acrylate of an aliphatic alcohol having from 1 to 30carbon atoms, with MFI of not less than 100 g/10 min, the MFI (melt flowindex) being measured or determined at 190° C. using a test weight of2.16 kg, or B2) a highly branched or hyperbranched polycarbonate with anOH number of from 1 to 600 mg KOH/g of polycarbonate (to DIN 53240, Part2), or B3) a highly branched or hyperbranched polyester of A_(x)B_(y)type, where x is at least 1.1 and y is at least 2.1, or B4) apolyalkylene glycol ester (PAGE) with low molecular weight of theformula (I)R—COO—(Z—O)_(n)OC—R  (I) in which R is a branched or straight-chainalkyl group having from 1 to 20 carbon atoms, Z is a branched orstraight-chain C₂ to C₁₅ alkylene group, and n is a whole number from 2to 20, or a mixture of B1) with B2) or of B2) with B3) or of B1) withB3) or of B1) with B2) and with B3) or of B1) with B4) or of B2) withB4) or of B3) with B4) or a ternary mixture of components B1) to B4), ineach case with A), where a secure interlock connection between parentbody and thermoplastic is achieved by way of the galvanized iron surfaceof the parent body, the surface of which has been pretreated by aprocess selected from the group consisting of acid treatment, sodatreatment, amine treatment, anodic treatment, base treatment and lasertreatment, and the said lightweight component is installed within themotor vehicles, rail vehicles, aircraft, ships, sleds or motor scooters.